Exodus 16:18, 33, 36

So when they measured it by omers, he who gathered much had nothing left over, and he who gathered little had no lack. Every man had gathered according to each one’s need.

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

Now an omer is one-tenth of an ephah.