Exodus 31:16

Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual covenant.

Therefore the children of Israel shall keep the Sabbath, to observe the Sabbath throughout their generations, for a perpetual covenant.

Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual covenant.

and the sons of Israel have observed the sabbath; to keep the sabbath to their generations `is' a covenant age-during,

The Israelites must keep the Sabbath, celebrating it as a permanent covenant for the generations to come.