Exodus 15:27-16:10
And they came to Elim, where there were twelve springs of water and seventy palm trees; and they encamped there beside the water.
Setting out from Elim, the whole Israelite community came to the wilderness of Sin, which is between Elim and Sinai, on the fifteenth day of the second month after their departure from the land of Egypt. In the wilderness, the whole Israelite community grumbled against Moses and Aaron. The Israelites said to them, "If only we had died by the hand of the Lord in the land of Egypt, when we sat by the fleshpots, when we ate our fill of bread! For you have brought us out into this wilderness to starve this whole congregation to death."
And the Lord said to Moses, "I will rain down bread for you from the sky, and the people shall go out and gather each day that day's portion--that I may thus test them, to see whether they will follow My instructions or not. But on the sixth day, when they apportion what they have brought in, it shall prove to be double the amount they gather each day." So Moses and Aaron said to all the Israelites, "By evening you shall know it was the Lord who brought you out from the land of Egypt; and in the morning you shall behold the Presence of the Lord, because He has heard your grumblings against the Lord. For who are we that you should grumble against us? Since it is the Lord," Moses continued, "who will give you flesh to eat in the evening and bread in the morning to the full, because the Lord has heard the grumblings you utter against Him, what is our part? Your grumbling is not against us, but against the Lord!"
Then Moses said to Aaron, "Say to the whole Israelite community: Advance toward the Lord, for He has heard your grumbling." And as Aaron spoke to the whole Israelite community, they turned toward the wilderness, and there, in a cloud, appeared the Presence of the Lord.