Leviticus 23:39; Leviticus 23:41

39 'On exactly the fifteenth day of the seventh month, when you have gathered in the crops of the land, you shall celebrate the feast of the LORD for seven days, with a rest on the first day and a rest on the eighth day.

41 'You shall thus celebrate it as a feast to the LORD for seven days in the year. It shall be a perpetual statute throughout your generations; you shall celebrate it in the seventh month.