Exodus 12:20

12:20 Ye shall eat nothing leavened; in all your habitations shall ye eat unleavened bread.

Exodus 31:16

31:16 Wherefore the children of Israel shall keep the sabbath, to observe the sabbath throughout their generations, [for] a perpetual covenant.

Exodus 38:4

38:4 And he made for the altar a brasen grate of network under the compass thereof beneath unto the midst of it.