Sefirat Haomer

According to Shulĥan Arukh , the customs of mourning begin on the first day of the omer and last until the morning of the 34th.

The days between Pesaĥ and Shavu’ot are days of sorrow, because 24,000 of R. Akiva’s students died during that period. Therefore, we keep some customs of mourning during this period.

If, at a time when it is permissible to count, one’s friend asks him, “What is today’s omer count?” one should not answer, “Today is day such-and-such of the omer,” unless he has already counted with a berakha.

women are exempt from the mitzva of sefirat ha-omer, as it is dependent on time. However, a woman who wants to perform this mitzva may do so.

One who is uncertain whether he neglected to count one day may continue counting with a berakha, because we only defer to the opinion that one cannot continue counting with a berakha when one is certain that he missed a day.

According to Behag, it is one long mitzva that extends from Pesaĥ to Shavu’ot. However, most poskim maintain that each night’s count is a separate mitzva.

If one regularly prays Ma’ariv at a late hour all year round, it is best that he count after praying at his regular time. However, if one is preoccupied and cannot pray Ma’ariv with a minyan after tzeit, and he intends instead to pray by himself later on, he should preferably count the omer right after tzeit, in order to fulfill the mitzva as soon as possible.

A fundamental question about sefirat ha-omer is whether the mitzva is mandated by Torah law or rabbinical enactment while the Temple no longer stands.

We begin to count the omer on the night of the sixteenth of Nisan. “From when the sickle is first put to the standing grain” refers to the omer harvest.