Exodus 34:20-22

Young's Literal Translation

²⁰ and the firstling of an ass thou dost ransom with a lamb; and if thou dost not ransom, then thou hast beheaded it; every first-born of thy sons thou dost ransom, and they do not appear before Me empty.

²¹ `Six days thou dost work, and on the seventh day thou dost rest; in ploughing-time and in harvest thou dost rest.

²² `And a feast of weeks thou dost observe for thyself; first-fruits of wheat-harvest; and the feast of in-gathering, at the revolution of the year.