Leviticus 23:1-3

The LORD said to Moses, “Give the following instructions to the people of Israel. These are the LORD’s appointed festivals, which you are to proclaim as official days for holy assembly. “You have six days each week for your ordinary work, but the seventh day is a Sabbath day of complete rest, an official day for holy assembly. It is the LORD’s Sabbath day, and it must be observed wherever you live.