John Gill Commentary Matthew 15:33

"And the disciples say unto him, Whence should we have so many loaves in a desert place as to fill so great a multitude?" — Matthew 15:33 (ASV)

And his disciples said to him
The former miracle of feeding five thousand men, besides women and children, with five loaves and two fishes, being quite out of their thoughts, they reply,

from where should we have so much bread in the wilderness, as to fill so
great a multitude?
The question is big with objections, and is put with some vehemency and astonishment: the people to be led were a multitude, a great multitude, a very great multitude, and these too had had but little, or no food, for a great while; and therefore would require the more to fill and satisfy them; and besides, it was a wilderness where they were, and where no provisions were to be had; and if they could have been got for money, they had not stock enough to purchase such a large number of loaves, as were necessary to feed so great a company with.