Leviticus 23:37-40

37These are the set feasts of the LORD, which ye shall proclaim to be holy convocations, to offer an offering made by fire unto the LORD, a burnt offering, and a meal offering, a sacrifice, and drink offerings, each on its own day:

38beside the sabbaths of the LORD, and beside your gifts, and beside all your vows, and beside all your freewill offerings, which ye give unto the LORD.

39Howbeit on the fifteenth day of the seventh month, when ye have gathered in the fruits of the land, ye shall keep the feast of the LORD seven days: on the first day shall be a solemn rest, and on the eighth day shall be a solemn rest.

40And ye shall take you on the first day the fruit of goodly trees, branches of palm trees, and boughs of thick trees, and willows of the brook; and ye shall rejoice before the LORD your God seven days.