Deuteronomy 15:18

15:18 You should not consider it difficult to let him go free, for he will have served you for six years, twice the time of a hired worker; the Lord your God will bless you in everything you do.

Deuteronomy 16:8

16:8 You must eat bread made without yeast for six days. The seventh day you are to hold an assembly for the Lord your God; you must not do any work on that day.