Exodus 23:16
And the feast of harvest, the first fruits of your labors, which you have sown in the field: and the feast of ingathering, which is in the end of the year, when you have gathered in your labors out of the field.
Nave's Topical Index—AKJV

Exodus 34:22
And you shall observe the feast of weeks, of the first fruits of wheat harvest, and the feast of ingathering at the year's end.
Nave's Topical Index—AKJV

Leviticus 23:15-21
And you shall count to you from the morrow after the sabbath, from the day that you brought the sheaf of the wave offering; seven sabbaths shall be complete:
Nave's Topical Index—AKJV

Numbers 28:26-31
Also in the day of the first fruits, when you bring a new meat offering to the LORD, after your weeks be out, you shall have an holy convocation; you shall do no servile work:
Nave's Topical Index—AKJV

Deuteronomy 16:9-12,16
Seven weeks shall you number to you: begin to number the seven weeks from such time as you begin to put the sickle to the corn.
Nave's Topical Index—AKJV