For the children of Israel walked forty years in the wilderness, until all the nation, even the men of war who came forth out of Egypt, were consumed, because they didn't listen to the voice of Yahweh: to whom Yahweh swore that he wouldn't let them see the land which Yahweh swore to their fathers that he would give us, a land flowing with milk and honey.
With the completion of the circumcision, the people could celebrate the Passover (something that an uncircumcised person was not allowed to do; see Exodus 12:47-49). The journey from Egypt to Canaan was now officially over, and therefore the miraculous daily supply of manna ceased (10-12; cf. Exodus 16:35).