Leviticus 23:33-36

And Jehovah spake unto Moses, saying, Speak unto the children of Israel, saying, On the fifteenth day of this seventh month is the feast of tabernacles for seven days unto Jehovah. On the first day shall be a holy convocation: ye shall do no servile work. Seven days ye shall offer an offering made by fire unto Jehovah: on the eighth day shall be a holy convocation unto you; and ye shall offer an offering made by fire unto Jehovah: it is a solemn assembly; ye shall do no servile work.