Exodus 16:4-8

Then the LORD said to Moses, “I will rain down bread from heaven for you. The people are to go out each day and gather enough for that day. In this way I will test them and see whether they will follow my instructions. On the sixth day they are to prepare what they bring in, and that is to be twice as much as they gather on the other days.” So Moses and Aaron said to all the Israelites, “In the evening you will know that it was the LORD who brought you out of Egypt, and in the morning you will see the glory of the LORD, because he has heard your grumbling against him. Who are we, that you should grumble against us?” Moses also said, “You will know that it was the LORD when he gives you meat to eat in the evening and all the bread you want in the morning, because he has heard your grumbling against him. Who are we? You are not grumbling against us, but against the LORD.”