Our text speaks of what happened the day following the feeding of the 5,000. Two days before Jesus and His disciples had crossed the Sea of Galilee from west to east. The next day He preached the Gospel and fed the 5,000. That evening He dismissed the disciples and He went up on the mountain to pray. The disciples boarded a boat and began to cross to the western shore. A severe storm came up and Jesus came to His disciples, walking on the water. He boarded the boat and they came to land. The next morning the crowd looked for Jesus. This is where we pick up the account at verse 24.
This happened on the day following the feeding of the 5,000. "There" was Bethsaida Julias where the miracle had been performed.
We are now in the synagogue at Capernaum, verse 59.
"After they had found Him." They call him rabbi. This crowd was respectful to Jesus but they were unbelievers. They ask Him: "When did you get here?" What they did not know was that He had crossed the sea in a miraculous manner. They must have been aware of the storm on the lake during the night. They are amazed at the fact that He got there so quickly. The "when" also includes the "how."
The expression "in very truth I say to" occurs here and in verse 32. Jesus uses it here because the people themselves did not know their own true character so well as did Jesus. For their own good He tells them. Their motive is utterly carnal. Note that Jesus did not answer their question.
Lenski: He replies to men's hearts not merely to their words.
This verse contains a prohibition, then a command followed by an explanation. Jesus uses the word "work" of the attitude and endeavor of the regenerate Christian. Its true character unfolds in verses 27-29. In verse 27 Jesus means "make the lasting food your constant endeavor." In verse 28 the mob uses the same word in a work-righteous manner. And in verse 30 they use the same word with reference to Jesus as if He had never done a sign.
Jesus compares the temporary good with the eternal food. Daily food and eternal food are both a gift of God. Where you have the one, you have the other. Who will give this gift? The Son of Man. Jesus is laying stress on His humanity which has received divine gifts from His divinity. Jesus uses the word "endures" or "remains" to get their minds off of mere physical food. But the crowd returns to the use of the word "bread" in verse 31. Jesus goes along with them and uses the word "bread," but in a different sense: It is heavenly, genuine bread, God's gift to them. In verse 33 He adds that it constantly comes from heaven and gives spiritual life to the whole world, not just to the Jews. Then in verse 35 He identifies Himself with that bread. It is both living and life-giving. Manna was neither of these. It is received by faith, not by human endeavor, and lastingly does away with spiritual hunger and thirst. A masterpiece in train of thought.
This man standing before them is truly God. "Because God has set His seal" explains how this can happen.
Bengel: 'Has sealed' -- has pointed out and distinguished Him by this very miracle.
On the relative clause "which the Son of Man shall give you" Lenski remarks: "'shall give' removes every synergistic notion from the command 'work for'." And on "sealed" he writes: "The seal he affixed to Jesus these people had seen on the previous day in the miracles he worked especially in that of the bread."
In their question they lay stress on "we." "What must WE do in order that WE might work the works of God?"
Kretzmann: They were caught in the idea that there must be some merit on their part, that they must perform something for their salvation.
Lenski: These people imagine that there is an entire scale of such works, a multiplicity of meritorious deeds to be done by them . . . . Jesus speaks of grace; they think of work-righteousness.
They are thinking of the multitudinous legal works required by Judaism.
The proper understanding of this verse is crucial to the whole pericope. Note that "work" is singular. Furthermore, contextually "of God" must be subjective genitive in the sense of "which God gives." The verb "believe" is in the present tense, a continued believing.
Lutherans have a unique understanding of the word "faith."
Formula of Concord, S.D., Art. II, Free Will, 25-27 (Tappert p. 526 where John 6:29 and 44 are quoted): Holy Scripture ascribe conversion, faith in Christ, regeneration, renewal, and everything that belongs to its real beginning and completion in no way to the human powers of the natural free will, be it entirely or one-half or the least and tiniest part, but altogether and alone to the divine operation and the Holy Spirit, as the Apology declares.
Luther, Lenski, Ylvisaker, Kretzmann and Stoeckhardt are worth reading on verse 29.
Lenski: We, indeed, must do the believing, but our believing is the work of God.
Stoeckhardt: Faith is nothing but willingness, a work of man which pleases God. But God Himself and God alone works this willingness, brings about this work in man.
Luther: Faith is a divine work which God demands of us; but at the same time He Himself must implant it in us, for we cannot believe by ourselves.
The answer in verses 30-31 betrays their spiritual blindness. Though they had witnessed a sign they now ask Jesus to work one so that they believe.
Luther: The learned and the work-righteous always know better. They love God as lice love a tramp; far from being interested in his welfare, their one concern is to feed on him and suck his blood.
Whenever man prescribes a condition on which he will believe, it is not faith but work-righteousness which is speaking.
They back up their statement with Scripture. What are they saying?
Here is another "In very truth I tell you." Jesus uses it to correct them. The Father, not Moses, gave them manna.
Furthermore, the genuine bread from heaven is a present fact, a gift of God. Note that the verb "gives you" denotes a permanent giving. Manna was very temporary. Manna was not the genuine, heavenly bread. It was only a type thereof.
As Jesus is standing there He is offering Himself to these unbelievers.
Luther: Christ denies Moses all power to help obtain eternal life.
Lenski: Note the contrasts: Moses -- my Father; did not give -- is giving; bread out of heaven, as these people understand it -- bread out of heaven, as Jesus understands it; out of heaven, not applicable to the manna, which never was in heaven -- out of heaven, applicable to the genuine bread, which actually was in heaven and actually comes down out of heaven.
This verse explains Jesus' previous statement. "Of God" distinguishes this bread from all others. Jesus is, of course, speaking of Himself when He says: "Which comes down from heaven and gives life to the world." Jesus differs from manna in these respects:
Manna merely sustained life, and was limited to the covenant people. Manna was given to living people to keep them alive. The genuine bread gives life to people who are dead, spiritually dead.
LB, TEV, NIV, JB and NEB translate "Sir." That is very likely correct because they are still unbelievers. Compare their answer with that of the Samaritan woman at 4:15. They really do want this bread, but they think that Jesus is speaking only of physical bread.
"Of life" means both "living" in verse 51 and "life-giving" in verse 54. Manna was neither of these.
Bengel: 'I am' -- To those who seek Him, He offers Himself immediately.
Luther: To come to Christ is the same as to believe in Christ . . . He is speaking of bread in the sense of coming to Christ, that is, believing in Christ. For to eat, to come to Christ, and to believe in Christ are all one and the same thing . . . It is obvious, therefore, that in this chapter the Lord is speaking of spiritual eating.
Lenski: 'The bread of life' like 'the water of life' in chapter four is Biblical allegory which unites the figure 'bread' with the reality 'life' and thus always interprets itself.
Westcott: This form of expression (I am) is not found in the Synoptists. It occurs not infrequently in John's Gospel, and the figures with which it is connected furnish a complete study of the Lord's work.
This is the first of the seven "I am" passages in this Gospel. It is repeated in verses 41, 48, and 51 in this chapter. The others are found at 8:12; 10:7-9; 10:11; 11:25: 14:6; and 15:1-5. The combination "I am" with reference to Christ also appears in 4:26; 6:20; 8:18; 13:19; 14:3 and 18:5. In each case it means: "I (and no one else) am, etc."
The American Edition of Luther's Works, Vol. 23, pp 5-45, contains Luther's sermon on this text. Much can be learned from reading this sermon.