Exodus 13:6

13:6 For seven days you must eat bread made without yeast, and on the seventh day there is to be a festival to the Lord.

Exodus 21:2

Hebrew Servants

21:2 “If you buy a Hebrew servant, he is to serve you for six years, but in the seventh year he will go out free without paying anything.

Exodus 34:21

34:21 “On six days you may labor, but on the seventh day you must rest; even at the time of plowing and of harvest you are to rest.