You are to count off seven weeks from the time you first put the sickle to the standing grain.

Exodus 23:16
You are also to keep the Feast of Harvest with the firstfruits of the produce from what you sow in the field. And keep the Feast of Ingathering at the end of the year, when you gather your produce from the field.

Exodus 34:22
And you are to celebrate the Feast of Weeks with the firstfruits of the wheat harvest, and the Feast of Ingathering at the turn of the year.

Leviticus 23:15
From the day after the Sabbath, the day you brought the sheaf of the wave offering, you are to count off seven full weeks.

Numbers 28:26
On the day of firstfruits, when you present an offering of new grain to the LORD during the Feast of Weeks, you are to hold a sacred assembly; you must not do any regular work.

Deuteronomy 16:10
And you shall celebrate the Feast of Weeks to the LORD your God with a freewill offering that you give in proportion to how the LORD your God has blessed you,

Ruth 2:23
So Ruth stayed close to the servant girls of Boaz to glean grain until the barley and wheat harvests were finished. And she lived with her mother-in-law.

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.