Exodus 16:1-5, 22-26

And they took their journey from Elim, and all the congregation of the children of Israel came unto the wilderness of Sin, which is between Elim and Sinai, on the fifteenth day of the second month after their departing out of the land of Egypt. And the whole congregation of the children of Israel murmured against Moses and Aaron in the wilderness: and the children of Israel said unto them, Would to God we had died by the hand of the LORD in the land of Egypt, when we sat by the flesh pots, and when we did eat bread to the full; for ye have brought us forth into this wilderness, to kill this whole assembly with hunger. 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 it came to pass, that on the sixth day they gathered twice as much bread, two omers for one man: and all the rulers of the congregation came and told Moses. And he said unto them, This is that which the LORD hath said, To morrow is the rest of the holy sabbath unto the LORD: bake that which ye will bake to day, and seethe that ye will seethe; and that which remaineth over lay up for you to be kept until the morning. And they laid it up till the morning, as Moses bade: and it did not stink, neither was there any worm therein. And Moses said, Eat that to day; for to day is a sabbath unto the LORD: to day ye shall not find it in the field. Six days ye shall gather it; but on the seventh day, which is the sabbath, in it there shall be none.