John Gill Commentary John 6:14

"When therefore the people saw the sign which he did, they said, This is of a truth the prophet that cometh into the world." — John 6:14 (ASV)

Then those men
The five thousand men, who had been fed with the loaves and fishes:

when they had seen the miracle that Jesus did ;
in feeding so many of them, with so small a quantity of food; in multiplying the provision in such a prodigious manner, that after they had eaten to the full, so many baskets of fragments were taken up:

said, this is of a truth that prophet that should come into the
world ;
meaning that prophet, that Moses spoke of, in (Deuteronomy 18:15) ; for the ancient Jews understood this passage of the Messiah, though the modern ones apply it to others; (See Gill on Acts 3:22). And these men concluded that Jesus was that prophet, or the true Messiah, from the miracle he wrought; in which he appeared, not only to be like to Moses, but greater than he.