Why the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual covenant.
a perpetual covenant
Genesis 9:13 I do set my bow in the cloud, and it shall be for a token of a covenant between me and the earth.
Genesis 17:11 And you shall circumcise the flesh of your foreskin; and it shall be a token of the covenant between me and you.
Jeremiah 50:5 They shall ask the way to Zion with their faces thitherward, saying, Come...