Exodus 16:32-33

32Then Moses said, “This is what Adonai has commanded. Let a full omer of it be kept throughout your generations, so that they may see the bread with which I fed you in the wilderness, when I brought you out from the land of Egypt.”

33Moses said to Aaron, “Take a jar and put a full omer of manna inside. Store it up before Adonai, to be kept throughout your generations.”