Sefirat haOmer - Counting the Omer

(1) And the ETERNAL spoke unto Moses, saying:... (4) These are the appointed seasons of the ETERNAL, even holy convocations, which ye shall proclaim in their appointed season. (5) In the first month, on the fourteenth day of the month at dusk, is the ETERNAL’S passover. ...(9) And the ETERNAL spoke unto Moses saying: (10) Speak unto the children of Israel, and say unto them: When ye are come into the land which I give unto you, and shall reap the harvest thereof, then ye shall bring the Omer of the first-fruits of your harvest unto the priest. (11) And he shall wave the Omer before the ETERNAL, to be accepted for you; on the morrow after the sabbath the priest shall wave it. ...(15) And ye shall count unto you from the morrow after the day of rest, from the day that ye brought the Omer of the waving; seven weeks shall there be complete; (16) even unto the morrow after the seventh week shall ye number fifty days; and ye shall present a new meal-offering unto the ETERNAL....(21) And ye shall make proclamation on the selfsame day; there shall be a holy convocation unto you; ye shall do no manner of servile work; it is a statute for ever in all your dwellings throughout your generations. (22) And when ye reap the harvest of your land, thou shalt not wholly reap the corner of thy field, neither shalt thou gather the gleaning of thy harvest; thou shalt leave them for the poor, and for the stranger: I am the ETERNAL your God.

(9) Seven weeks shalt thou number unto thee; from the time the sickle is first put to the standing corn shalt thou begin to number seven weeks. (10) And thou shalt keep the feast of weeks unto the ETERNAL thy God after the measure of the freewill-offering of thy hand, which thou shalt give, according as the ETERNAL thy God blesseth thee.

(1) It is customary not to get married between Pesach and Shavuot, until Lag BaOmer (the 33rd day), because during that time, the students of Rabbi Akiva died. However, to do "erusin" and "kiddushin" (engagement and betrothal) is OK. And even for "nisuin" (marriage), if someone did so, we do not punish him. Rema: however, from Lag Ba'Omer onwards, all this is permitted (Abudraham, Beit Yosef & Minhagim).

(2) It is customary not to cut one's hair until Lag BaOmer, since it is said that that is when they stopped dying. One should not cut one's hair until the 34th day, in the morning, unless the 33rd day falls on Friday, in which case one may cut one's hair then, in honor of the Sabbath ("kavod Shabbat"). Rema: But in these countries, we do not follow the custom he advocates; rather, we cut our hair on the 33rd day, and we rejoice a bit, and we do not say Tachanun (Maharil and Minhagim). And one should only cut one's hair on the 33rd day itself, but not on its evening. However, if it falls on Sunday, our custom is to cut our hair on Friday in honor of the Sabbath (Maharil). Someone who is performing a brit milah (i.e., the sandak, mohel and the infant's father), or circumcizing his son, is allowed to cut his hair during sefirah in honor of the circumcision (Hagahot Minhagim).