GENERAL LAWS
The Torah states: “And you shall count for yourselves seven weeks from the day following the Shabbat, from the day of bringing the omer.” Chazal taught us that the “Shabbat” mentioned in this verse is actually the first day of the holiday of Pesach, which is also called “Shabbat.” Therefore, at the conclusion of the first day of Pesach, we begin counting the Omer and this continues for the seven weeks.
The Zohar explains the extreme importance of counting the Omer, as follows: “Every person who doesn’t count this number of the seven complete weeks, to merit this purity, is not called pure, and has nothing to do with purity, and is not worthy of having a share in the Torah.”
Some authorities maintain that during the half hour period before one can count the Omer, i.e., the half hour prior to sunset, one is prohibited to have a meal, and may only eat a snack, less than a k’beitza of bread. If one started eating anyway during this half-hour, some say that when the time comes to count the Omer one must stop to count the Omer, whereas others say that one does not need to stop eating. It is best in this situation to stop the meal, count the Omer and then continue eating.
It is permitted to eat fruits and similar foods before counting the Omer.
It is customary to say the L’sheim Yichud before counting the Omer. One should try to avoid saying the verse Usfartem lachem… sheva Shabbatot t’mimot tih’yenah in the L’sheim yichud on the last day of counting the Omer. However, if one said it, one may count the Omer anyway with a bracha.
BRACHA
It is a mitzvah for every man to count the Omer.” However, if one had in mind to listen to somebody else’s bracha and then count the Omer, and the person reciting the bracha and counting had in mind to be motze the other, then b’di’avad he has fulfilled his obligation.
We do not recite Shehecheyanu on counting the Omer.
One must say the bracha and count the Omer standing. If one said the bracha and sefira while sitting, then b’di’avad he has fulfilled his obligation. Someone who is elderly or ill and has difficulty standing up may lechatchila count while sitting down.
Ideally, one should know before the bracha the number of days he will be counting. If one did not know, and said the bracha anyway, and had in mind to say whatever he hears from others, then b’di’avad he has fulfilled his obligation.
TIME
The mitzvah is to count the Omer at the very beginning of the night, after three stars are visible. Therefore, one should count sefira as soon as possible so as not to delay the mitzva. If one did not count at the beginning of the night, then b’di’avad one may count with a bracha the entire night, until dawn.
One can count sefira before Arvit, as long as it is after Tzeit hakochavim. Some are particular to count the Omer after Arvit. If one is concerned that one will forget, one can count before Arvit.
Some have the custom to count after Kaddish Titkabbal after the Amidah of Arvit. The custom of Sephardim in Jerusalem is to count after Aleinu l’shabei’ach.
At the conclusion of Shabbat and Yom Tov we count the Omer before Havdalah, in order to delay the conclusion of Shabbat.
Tzeit hakochavim in Israel is thirteen and a half minutes after sunset. However, it is proper to be stringent and count when it is definitely night and one can really see stars, which is about twenty-five minutes after sunset. Other parts of the world should check the times printed in the local calendar.
It is customary to count the Omer after Shacharit without a bracha.
COUNTING THE OMER BY THE CHAZZAN
The custom is that the chazzan says the bracha and counts the Omer first, and afterwards the congregation say the bracha and counts. The congregation should have in mind not to fulfill their obligation with the bracha of the chazzan.
In some communities the chazzan says the bracha and counts after the congregation, in order to ensure that the chazzan won’t be motze anyone in the congregation.
Someone who cannot recite the bracha because he forgot to count a day should have in mind to be yotze with the bracha of the chazzan. It is recommended for the chazzan to always have in mind that he intends that his bracha should only be motze those who cannot say the bracha themselves.
AFTER SEFIRAT HA’OMER
It is good practice after counting sefirat ha’omer to have in mind one of the words of the Mizomor Lamnatzei’ach binginot (Tehillim 67), one letter from the verse Yism’chu viran’nu, one letter from the prayer Ana b’cho’ach, and the s’firah (divine emanation) of that night. Therefore, on the first night of sefira one should have in mind the letter Yud from Yism’chu, the letter Aleph from Ana b’cho’ach, the word Elokim from Psalm 67, and the s’firah of chesed sheb’chesed.
On the second night one should have in mind the letter Sin of Yism’chu, the letter Bet of Ana b’cho’ach, the word Y’chonenu of Psalm 67, and the s’firah of g’vurah sheb’chesed.
After counting one says Harachaman, Ana b’cho’ach, and Lamnatzei’ach binginot. It is auspicious to read it from a Siddur where it is shaped like a menorah.
ONE WHO FORGOT OR MADE A MISTAKE
If one forgot to count sefirat ha’omer at night, one should count during the day (until sunset) without a bracha. Some say that one can even count until the end of twilight, and even if one already davenned Arvit of the next day. In these cases, one may continue counting on subsequent nights with a bracha. If one forgot to count sefirat ha’omer during the day as well, one should count without a bracha during the coming nights.
If one remembered after sunset, before Tzeit hakochavim, one should count immediately without a bracha. There is a disagreement as to whether one can then count with a bracha on subsequent days, and the custom is to be lenient; that one may count during the coming days with a bracha.
If one forgot to count an entire day and night, one may not recite the bracha during the coming nights. Nevertheless, one is obligated to continue counting without a bracha. It is good to listen to the bracha of another, and the individual saying the bracha should have in mind to be motze the other. Alternatively, one can listen to the bracha of the chazzan. If nobody can say the bracha for him, he should say the bracha without Hashem's Name and malchut and think about Hashem's Name and malchut.
If one erred and counted the wrong number: if one remembers during the night, one should recite again the bracha and count the correct number. If one remembers during the day, one should count correctly without a bracha, and during the coming nights one may count with a bracha. However, if one did not realize the mistake until the next night, one may not continue counting with a bracha.
Someone who counted the correct number of days but counted the incorrect number of weeks, may count during the coming nights with a bracha.
Someone who forgot to count the Omer on Lag B’omer, but said, “Today is Lag B’omer” in the course of speaking with his friends, may continue counting during the coming nights with a bracha.
Some have the custom to mention the Omer when writing a letter, and write at the top of the page, “Today is such and such of the Omer.” Some have the custom to write: היום כך וכך למ"ט מונים. If one wrote this, and forgot to count on that day, some authorities say that he may count during the coming nights with a bracha.
MISCELLANEOUS ISSUES IN SEFIRAT HA’OMER
If one counted without saying the bracha, one has fulfilled the obligation. Therefore, when someone asks his friend during twilight or afterwards “How many days is it today,” he should tell him, “Yesterday was such-and-such.” If he tells him how many days it is today, he is not allowed to say a bracha that night and needs to count without a bracha.
If one answered by saying the days only, or the weeks only, e.g., on the seventh day one answered, “Today is one week,” one may not count that night with a bracha and should count without a bracha. Some are particular about this only from twilight onwards, but it is best to be careful about this from P’lag HaMinchah (one and a quarter hour before night) onwards. However, if one answered one’s friend before P’lag HaMinchah, one may count that night with a bracha.
Some authorities are lenient and say that if one did not say first “Today is” before saying the number, one may count that night with a bracha. Some are even more lenient, and say that even if one said, “Today is number such-and-such,” one may count that night with a bracha, as long as one did not have in mind to fulfill the mitzvah when one said it.
If one counted by saying a letter of the Hebrew alphabet that corresponds to the proper number, for instance Hayom gimel yamim instead of Hayom sh’loshah yamim, one does not need to count again with a bracha. However, one should count again in the regular way, without a bracha. If one did not count again normally, one may nevertheless count on the following nights with a bracha. Therefore, one should be especially careful on the evening of Lag B’omer not to say “Lag B’omer” until one says the bracha and counts. (“Lag” stands for Lamed-Gimel, corresponding to thirty-three.)
If, when one said the bracha, one had in mind to count day four, and after the bracha realized that it was day five, he should count five, and there is no need to recite the bracha again. Similarly, if one made a mistake in the actual counting; e.g. if it was days six and he counted five, he should immediately count again with the correct number, and there is no need to recite the bracha again. However, if one did not correct the mistake within a few seconds (toch k’dei dibbur) after counting the wrong number, one must recite the bracha a second time and count correctly.
If one knew the correct day when saying the bracha, but counted incorrectly, some authorities say that one does not need to recite the bracha again. Others disagree, and therefore one should recite the bracha without mentioning Hashem's Name or malchut (instead, one should think of Hashem's Name and malchut) and then count.
Someone who is unsure which day of the Omer it is, should not recite the bracha and count until he has clarified what is the correct number to count. If one counted without a bracha, and the next day he determined that he in fact counted correctly, he may continue to count on the following nights with a bracha.
In this situation, a viable solution is to say, “Today is such-and-such of the Omer,” and then again say, “Today is another-such-and-such of the Omer,” and that way, if one later determines that one of them was correct, one may continue counting with a bracha during the rest of the nights.
WHO IS EXEMPT FROM COUNTING THE OMER
Women: Women are exempt from counting the Omer. According to Kabbalah, they must not count the Omer at all. Nevertheless, they must observe the customs of mourning (not cutting hair, etc.) like men.
Children: It is a mitzvah to educate one’s sons to count the Omer. They should recite a bracha before counting. If they forgot to count one day, they should count during the coming nights without a bracha.
A boy who becomes bar-mitzvah: A boy who became bar-mitzvah during the Omer, who counted correctly every night before his bar-mitzvah, may continue to count with a bracha now that he is bar-mitzvah.
Onen: One whose immediate family member has passed away and has not yet been buried is called an Onen. An Onen is exempt from all the Mitzvot in the Torah. If one is an Onen at night one, he should wait to count until after the burial the next day without reciting the bracha. During the coming nights he may count with a bracha. If one is certain that he will be an Onen throughout the entire coming day (i.e., the burial will be delayed), he should count at night without a bracha, and may count during the coming nights with a bracha. If possible, he should count after the Chevra Kaddisha have taken charge of the burial arrangements. The Mishnah B’rurah adds that if an Onen did not count throughout the night and day, he should count during the coming nights without a bracha, even though he was exempt from counting the Omer whilst he was an Onen.
CUSTOMS OF MOURNING DURING THE OMER
During the days of the Omer, the students of Rabbi Akiva died, over a period of thirty-three days. Therefore, we observe several mourning practices during part of the Omer. However, this does not apply to the entire period of the Omer, as will be explained below.
Sephardim: Those who follow the ruling of the Beit Yosef do not take haircuts or get married until the morning of the thirty-fourth day of the Omer. Similarly, during these days, listening to music, whether instrumental or on the radio, is prohibited.
The Ari"zal: His custom was not to have a haircut throughout the Omer until the day before Shavu'ot. According to this custom, even a groom on his wedding day should not take a haircut or shave during the Omer.
Ashkenazim in Israel who follow the Ari"zal: Their custom is allow marriage and haircuts on the thirty-third day of the Omer (Lag B’omer), and from Rosh Chodesh Sivan. However, before and on Rosh Chodesh Iyar, between Rosh Chodesh Iyar and Lag B’omer, and between Lag B’omer and Rosh Chodesh Sivan, they observe the customs of mourning. Most of them only take a haircut on the day of Lag B’omer, and not at night. Similarly, marriages are held on the day of Lag B’omer, and not at night. However, under pressing circumstances, they may take haircuts or get married on the night of Lag B’omer. Nowadays, many are lenient and get married on the night of Lag B’omer.
Some Ashkenazim have the custom to permit haircuts and marriages until Rosh Chodesh Iyar, and then prohibit them until Shavu'ot, except for on Lag B’omer. Some are stringent and prohibit them on both days of Rosh Chodesh Iyar, and permit them during the three days before Shavu'ot.
Marriage: The custom not to marry applies also to second marriages, including a widower who marries a widow. However, one may re-marry one’s ex-wife, even before Lag B’omer.
Engagement: One may get engaged and make a festive engagement meal. However, musical instruments are not allowed and dancing should be kept to a minimum. According to the Mishnah B’rurah, dancing is prohibited.
Bar-mitzvah: One who becomes bar-mitzvah during the Omer is called up to the Torah, and one may make a meal in honor of the bar-mitzvah and sing. Musical instruments, however, are not allowed.
Songs: One should be careful not to listen to even holy songs, from a radio or other media until Lag B’omer.
Cutting hair: The Sephardim customarily do not cut hair until the morning of the thirty-fourth day of the Omer, because that was when the students of Rabbi Akiva stopped dying. One may have a haircut from then on, until Shavu'ot.
It is the custom of the Ari"zal not to take a haircut until the day before Shavu'ot. According to the Rema, one may take a haircut during the day of Lag B’omer, but not at night. The Mishnah B’rurah permits haircuts on the night of Lag B’omer.
If Lag B’omer is on a Friday, Ashkenazim cut their hair in honor of Shabbat.
If Lag B’omer falls on Motza’ei Shabbat, according to the Beit Yosef, one may not have a haircut on Friday. According to the Rema, it is permissible.
According to the Ari"zal, even though, one should not have a haircut until the day before Shavu'ot, if Shavu'ot falls on a Sunday, one should cut one’s hair on the previous Friday.
Brit Milah (Circumcision): The sandak, mohel and the father of the baby may take haircuts and shave on the day of the Brit Milah and even on the day preceding from the late afternoon onwards. However, the custom of the Ari"zal is to not cut one’s hair at all.
Cutting nails: It is permissible to cut one’s nails throughout the Omer.
Shehecheyanu: Some have the custom not to recite Shehecheyanu on clothes or fruit. Others recite on fruit but not clothes. According to both customs, one may buy new clothes during the Omer and wear them afterwards. However, the accepted custom is to recite Shehecheyanu on both clothes and fruit.
Melacha (work): It is customary for women not to do melacha from sunset until after counting the Omer, because that was the time of day that the students of Rabbi Akiva passed away. This is hinted at in the verseשבע שבתות , , from the root שבות, which means “abstain,” teaching us that one should abstain from work from sunset until one counts the Omer. (There are additional reasons for this.) Some have the custom to abstain from work all night. According to the Ben Ish Chai, it is proper for men to be careful about this too. However, this is only until Lag B’omer.