John Chrysostom — as excerpted in the Catena Aurea on John 6:47-51

“(Hom. xlvi. 2) The addition, In the wilderness, is not put in without meaning, but to remind them how short a time the manna lasted; only till the entrance into the land of promise. And because the bread which Christ gave seemed inferior to the manna, in that the latter had come down from heaven, while the former was of this world, He adds, This is the bread which cometh down from heaven.”