Deuteronomy 16:9-12

⁹Seven weeks shall you number to you: from the time you begin to put the sickle to the standing grain shall you begin to number seven weeks. ¹⁰You shall keep the feast of weeks to Yahweh your God with a tribute of a freewill-offering of your hand, which you shall give, according as Yahweh your God blesses you: ¹¹and you shall rejoice before Yahweh your God, you, and your son, and your daughter, and your man-servant, and your maid-servant, and the Levite who is within your gates, and the sojourner, and the fatherless, and the widow, who are in the midst of you, in the place which Yahweh your God shall choose, to cause his name to dwell there. ¹²You shall remember that you were a bondservant in Egypt: and you shall observe and do these statutes.