Exodus 31:15
King James Version
“Six days may work be done; but in the seventh is the sabbath of rest, holy to the LORD: whosoever doeth work in the sabbath day, he shall surely be put to death.”
Context
12And the LORD spake unto Moses, saying,
13Speak thou also unto the children of Israel, saying, Verily my sabbaths ye shall keep: for it is a sign between me and you throughout your generations; that ye may know that I the LORD that doth sanctify you.
14Ye shall keep the sabbath therefore; for it holy unto you: every one that defileth it shall surely be put to death: for whosoever doeth work therein, that soul shall be cut off from among his people.
15Six days may work be done; but in the seventh is the sabbath of rest, holy to the LORD: whosoever doeth work in the sabbath day, he shall surely be put to death.
16Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, a perpetual covenant.
17It a sign between me and the children of Israel for ever: for six days the LORD made heaven and earth, and on the seventh day he rested, and was refreshed.
18And he gave unto Moses, when he had made an end of communing with him upon mount Sinai, two tables of testimony, tables of stone, written with the finger of God.