Exodus 31:16
Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, for a perpetual covenant.
Cross-references
Exodus 23:12
Parallel
Exodus 23:12 repeats the Sabbath command with focus on rest for servants and animals, complementing the covenant sign aspect here.
Genesis 17:11
Parallel
Genesis 17:11 uses circumcision as a covenant sign, paralleling the Sabbath as a sign in Exodus 31:16.
Genesis 9:13
Related theme
Genesis 9:13 also describes a covenant sign — the rainbow — similar to how Exodus 31:16 calls the Sabbath a sign between God and Israel.