John Chrysostom — as excerpted in the Catena Aurea on John 6:1-14

“(Hom. xlii. 1) Nor did He only sit with His disciples, but conversed with them familiarly, and gained possession of their minds. Then He looked, and saw a crowd advancing. But why did He ask Philip that question? Because He knew that His disciples, and he especially, needed further teaching. For this Philip it was who said afterwards, Shew us the Father, and it sufficeth us. (c. 14:8) And if the miracle had been performed at once, without any introduction, the greatness of it would not have been seen. The disciples were made to confess their own inability, that they might see the miracle more clearly; And this He said to prove him.”