Exodus 16:32-34

Then Moses said, “This is the word which the LORD commands, ‘Let an omer of it be kept throughout your generations, that they may see the bread with which I fed you in the wilderness, when I brought you out of the land of Egypt.’ ” So Moses said to Aaron, “Take a pot and put an omer of manna in it, and place it before the LORD to be kept throughout your generations.” As the LORD commanded Moses, so Aaron [eventually] placed it in the presence of the Testimony, to be kept. [Heb 9:4]