And when Jesus knew it
As he did immediately, by his omniscience; for as he knew the thoughts and reasonings of the Scribes and Pharisees, ( Matthew 9:4 ) , so he did those of his own disciples:
he saith unto them, why reason ye because ye have no bread?
or imagine that I have given you this caution on that account; or are distressed because this is your case, as if you should be reduced to great difficulties, by reason of your forgetfulness and negligence:
perceive ye not yet, neither understand?
the meaning of the parabolical expressions, which he had used them to; or his power in providing food for them, and supporting a great number of persons with very little food, of which they had some very late instances:
have ye your heart yet hardened?
as after the first miracle; see ( Mark 6:52 ) , for it might have been expected, that by a second miracle of the loaves, their understandings would have been more enlightened, and their faith increased, and that they would have relinquished their gross notions, their anxieties, doubts, and unbelief.