Exodus 16:14-17

And when the dew had gone up, there was on the face of the wilderness a fine, flake-like thing, fine as frost on the ground. When the people of Israel saw it, they said to one another, “What is it?” For they did not know what it was. And Moses said to them, “It is the bread that the Lord has given you to eat. This is what the Lord has commanded: ‘Gather of it, each one of you, as much as he can eat. You shall each take an omer, according to the number of the persons that each of you has in his tent.’” And the people of Israel did so.