John 6:5
“Whence shall we have so many loaves, that these may eat?”
So in the Old [Testament] He spoke to Moses, for He wrought not the sign until He had asked him, “What is that in your hand?” Because things coming to pass unexpectedly and all at once, are wont to throw us into forgetfulness of things previous, therefore He first involved him in a confession of present circumstances, that when the astonishment should have come upon him, he might be unable afterwards to drive away the remembrance of what he had confessed, and thus might learn by comparison the greatness of the miracle, which in fact takes place in this instance; for Philip being asked, replied,
Source: Homilies on the Gospel of John (New Advent)