Leviticus 23:15
And ye shall count unto you from the morrow after the sabbath, from the day that ye brought the sheaf of the wave-offering; seven sabbaths shall there be complete:
Exodus 34:22
And thou shalt observe the feast of weeks, even of the first-fruits of wheat harvest, and the feast of ingathering at the year's end.
Leviticus 23:10-11
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 sheaf of the first-fruits of your harvest unto the priest:
Leviticus 25:8
And thou shalt number seven sabbaths of years unto thee, seven times seven years; and there shall be unto thee the days of seven sabbaths of years, even forty and nine years.
Deuteronomy 16:9-10
Seven weeks shalt thou number unto thee: from the time thou beginnest to put the sickle to the standing grain shalt thou begin to number seven weeks.
Numbers 28:26
Also in the day of the first-fruits, when ye offer a new meal-offering unto Jehovah in your feast of weeks, ye shall have a holy convocation; ye shall do no servile work;