John 6:6

And this he said to prove him
Or "tempting him", trying his faith, and not only his, but the rest of the disciples; not as ignorant of it himself, but in order to discover it to him and them, and to prepare them for the following miracle; and that it might appear the more illustrious and marvellous:

for he himself knew what he would do;
Christ had determined to work a miracle, and feed the large number of people that were with him, with that small provision they had among them; and being God omniscient, he knew that he was able to do it, and that he was determined to do it, and it would be done; but he was willing first to try the faith of his apostles.