Deuteronomy 8:3
8:3 So he humbled you by making you hungry and then feeding you with unfamiliar manna. He did this to teach you that humankind cannot live by bread alone, but also by everything that comes from the Lord’s mouth.
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.