Exodus 5:3

5:3 And they said, “The God of the Hebrews has met with us. Let us go a three-day journey into the desert so that we may sacrifice to the Lord our God, so that he does not strike us with plague or the sword.”

Exodus 31:14

31:14 So you must keep the Sabbath, for it is holy for you. Everyone who defiles it must surely be put to death; indeed, if anyone does any work on it, then that person will be cut off from among his people.