Jamieson, Fausset and Brown on Ezekiel 29:11

11. forty years--answering to the forty years in which the Israelites, their former bondsmen, wandered in "the wilderness" (compare Note, see on Eze 29:5). Jerome remarks the number forty is one often connected with affliction and judgment. The rains of the flood in forty days brought destruction on the world. Moses, Elias, and the Saviour fasted forty days. The interval between Egypt's overthrow by Nebuchadnezzar and the deliverance by Cyrus, was about forty years. The ideal forty years' wilderness state of social and political degradation, rather than a literal non-passing of man or beast for that term, is mainly intended (so Eze 4:6; Is 19:2, 11).