Exodus 31:16

¹⁴And ye shall keep the Sabbaths, because this is holy to the Lord for you; he that profanes it shall surely be put to death: every one who shall do a work on it, that soul shall be destroyed from the midst of his people.

¹⁵Six days thou shalt do works, but the seventh day is the Sabbath, a holy rest to the Lord; everyone who shall do a work on the seventh day shall be put to death.

— Exodus 31:16 —

¹⁷It is a perpetual covenant with me and the children of Israel, it is a perpetual sign with me; for in six days the Lord made the heaven and the earth, and on the seventh day he ceased, and rested.

¹⁸And he gave to Moses when he left off speaking to him in Mount Sinai the two tables of testimony, tables of stone written upon with the finger of God.