Joshua 5:4-7

This had to be done, because none of Israel's baby boys had been circumcised during the forty years that Israel had wandered through the desert after leaving Egypt. And why had they wandered for forty years? It was because straight after they left Egypt, the men in the army had disobeyed the LORD. And the LORD had said, “None of you men will ever live to see the land that I promised Israel. It is a land rich with milk and honey, and some day your children will live there, but not before you die here in the desert.”