Exodus 16:33-37

And Moses said unto Aaron, Take a pot, and put an omer full of manna therein, and lay it up before the LORD, to be kept for your generations.

As the LORD commanded Moses, so Aaron laid it up before the Testimony, to be kept.

And the children of Israel did eat manna forty years, until they came to a land inhabited; they did eat manna, until they came unto the borders of the land of Canaan.

Now an omer is the tenth part of an ephah.