Exodus 16:6 (KJV)

Then said the Lord unto Moses, Behold, I will rain bread from heaven for you; and the people shall go out and gather a certain rate every day, that I may prove them, whether they will walk in my law, or no.

And it shall come to pass, that on the sixth day they shall prepare that which they bring in; and it shall be twice as much as they gather daily.

And Moses and Aaron said unto all the children of Israel, At even, then ye shall know that the Lord hath brought you out from the land of Egypt:

And in the morning, then ye shall see the glory of the Lord; for that he heareth your murmurings against the Lord: and what are we, that ye murmur against us?

And Moses said, This shall be, when the Lord shall give you in the evening flesh to eat, and in the morning bread to the full; for that the Lord heareth your murmurings which ye murmur against him: and what are we? your murmurings are not against us, but against the Lord.