Exodus 16:15-16

When the sons 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 which the LORD has given you to eat. This is what the LORD has commanded, ‘Gather of it every man as much as he should eat; you shall take an omer apiece according to the number of persons each of you has in his tent.’ ”