Exodus 16:35

Israel did eat manna forty years That is, save one month, as appears from Joshua 5:11. As Moses did not live to see the cessation of the manna, some have supposed that the words of this verse were added by Ezra. But although Moses did not go into Canaan, yet he came to the borders of it, and he perfectly knew, both from the nature of the thing, and by revelation from God, that the manna would immediately cease upon their entering into Canaan; and therefore might well write in this manner.