This passage is known as a regular Jewish Midrash (Jewish commentary or exposition on Scripture. The forms varied considerably but often included reading a text in the light of other texts, with careful attention to all nuances of details supposedly filled with divine significance. Because such methods of reading Scripture were common, early Christians could employ them in relating their message to other ancient Jewish Bible readers.) It is also known as homily. See Exodus 16:15 and Psalm 78:24. Jesus quotes this in John 6:31. As a teacher, Jesus paraphrases, explains and expounds in a manner that is characteristic of ancient Jewish teachers. Even though He does this, His hearers fail to understand Him. Ancient teachers had a habit of making their lectures hard to understand. This would sort out genuine followers from the masses.
Jesus had escaped the crowd when He found out they wanted to make Him their king. At this time, they had not changed their mind. They attempted to lay hands on Him, but His hour had not come. Jesus still had more ministering to do before His hour of crucifixion. Like other ancient writers, John was free to paraphrase his material in his own words. Here the crowd cites Scripture as if they are rabbis in a debate. See http://ref.ly/Ex16.4 and http://ref.ly/Ps78.24. John uses both Hebrew and Greek versions of these texts.
The theme of this passage is “I Am the Bread of Life.”
The crowd sought to manipulate Jesus by having Him repeat the loaves and fishes. They had been taught by the rabbis that when Messiah would come, He would repeat what Moses had done by giving the manna. They could see that Jesus was the Messiah. It was only natural that they should look for Jesus to repeat what Moses had done. They expected Jesus to repeat it six times like Moses had repeated this same thing six times in one week for the entire forty years of wandering. (Midrash Mekilta on http://ref.ly/Ex16.25) “For whom has the manna been prepared? For the righteous in the age that is coming” (Midrash Tanchuma Beshallach 21:66). The first redeemer provided manna. The last redeemer (Jesus Christ) will bring down manna (Midrash Rabba on http://ref.ly/Ec1.9 [emphasis mine]
There is no doubt that this crowd had heard these sayings, and they were on their minds. When studying this passage, it would seem as though they were less desirous of the coming of the messianic age. Their aim was to manipulate Jesus into becoming what they wanted at that time. They were not looking for a spiritual leader with a spiritual kingdom. Jesus told them that He was God’s gift to men. God desired men to believe in Him. Their response was different from what was expected. They would not believe unless a sign was done. They sought more signs even though Jesus had healed people and fed the five thousand. They were after physical signs, and not spiritual signs.
Jesus had to correct their thinking. Moses did not give the manna. God did. The manna received by the Israelites was not the true bread sent from the true Heaven. It was earthly bread from the visible sky. It was temporary. The manna that Jesus is talking about is everlasting. They did not understand this. Jesus pointed to Himself as being that Heavenly manna. He is the only bread that can satisfy the real hunger of the human soul.