How much did Jesus know before he fed the five thousand?
Before feeding the five thousand, Jesus already knew exactly what He would do. He knew the end from the beginning and knew He was going to feed the 5,000 before the situation even presented itself. His question to Philip was a test, not because He lacked knowledge.
Les explains that in John 6, when Jesus asked Philip where they could buy bread, He was testing Philip, for He Himself knew what He would do. Jesus knew the end from the beginning; He knew He would feed the 5,000 before the situation even arose. Afterward, the disciples gathered twelve baskets of fragments, showing He could more than supply all of Israel's physical need because of who He was.
John 6:6
And this he said to prove him: for he himself knew what he would do.