Exodus 31:15

31:15 Six days shall work be done, but on the seventh day is a Sabbath of solemn rest, holy to Yahweh. Whoever does any work on the Sabbath day shall surely be put to death.
-World English Bible

Other Translation

31:15 Six days may work be done; but in the seventh [is] the sabbath of rest, holy to the LORD: whosoever doeth [any] work in the sabbath day, he shall surely be put to death.
-King James Version