What does Exodus 31:17 mean?

It's a permanent sign between me and the Israelites. In six days, the Lord made the sky and the earth, but on the seventh day, he stopped working and rested. Exodus 31:17 - Modern Text Bible

(The Sabbath is rooted in creation itself—God rested, so his people should too. It's about more than rules; it's about reflecting God's own rhythm.)