Leviticus 23:39 in the King James Version
Also in the fifteenth day of the seventh month, when ye have gathered in the fruit of the land, ye shall keep a feast unto the LORD seven days: on the first day shall be a sabbath, and on the eighth day shall be a sabbath.
Context
38 in addition to the Sabbaths of the LORD, and in addition to your gifts, and in addition to all your vows, and in addition to all your free will offerings, which you give to the LORD.
39 “‘So on the fifteenth day of the seventh month, when you have gathered in the fruits of the land, you 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.
40 You shall take on the first day the fruit of majestic trees, branches of palm trees, and boughs of thick trees, and willows of the brook; and you shall rejoice before the LORD your God seven days.