Jesus had just finished feeding them and they wanted more (GOJ chapter 6), Jesus made the analogy with the divine food from heaven, mana, which the Hebrews ate.
Words to the People
26 Jesus answered them and said, “Truly, truly, I say to you, you ( AH ) seek Me, not because you saw ( AI ) signs, but because you ate of the loaves and were filled. 27 Do not ( AJ ) work for the food which perishes, but for the food which endures to ( AK ) eternal life, which ( AL ) the Son of Man will give to you, for on Him the Father, God, ( AM ) has set His seal.” 28 Therefore they said to Him, “What shall we do, so that we may work the works of God?” 29 Jesus answered and said to them, “This is ( AN ) the work of God, that you believe in Him whom He ( AO ) has sent.” 30 So they said to Him, “ ( AP ) What then do You do for a ( AQ ) sign, so that we may see, and believe You? What work do You perform? 31 ( AR ) Our fathers ate the manna in the wilderness; as it is written, ‘ ( AS ) He gave them bread out of heaven to eat .’” 32 Jesus then said to them, “Truly, truly, I say to you, it is not Moses who has given you the bread out of heaven, but it is My Father who gives you the true bread out of heaven. 33 For the bread of God is that which ( AT ) comes down out of heaven, and gives life to the world.” 34 Then they said to Him, “Lord, always ( AU ) give us this bread.”
35 Jesus said to them, “ ( AV ) I am the bread of life; he who comes to Me will not hunger, and he who believes in Me ( AW ) will never thirst. 36 But ( AX ) I said to you that you have seen Me, and yet do not believe. 37 ( AY ) All that the Father gives Me will come to Me, and the one who comes to Me I will certainly not cast out. 38 For ( AZ ) I have come down from heaven, ( BA ) not to do My own will, but ( BB ) the will of Him who ( BC ) sent Me. 39 This is the will of Him who sent Me, that of ( BD ) all that He has given Me I ( BE ) lose nothing, but ( BF ) raise it up on the last day. 40 For this is the will of My Father, that everyone who ( BG ) beholds the Son and ( BH ) believes in Him will have eternal life, and I Myself will ( BI ) raise him up on the last day.”
Words to the Jews
41 ( BJ ) Therefore the Jews were grumbling about Him, because He said, “I am the bread that ( BK ) came down out of heaven.” 42 They were saying, “ ( BL ) Is not this Jesus, the son of Joseph, whose father and mother ( BM ) we know? How does He now say, ‘ ( BN ) I have come down out of heaven’ ?” 43 Jesus answered and said to them, “Do not grumble among yourselves. 44 No one can come to Me unless the Father who sent Me ( BO ) draws him; and I will ( BP ) raise him up on the last day. 45 It is written ( BQ ) in the prophets, ‘ ( BR ) And they shall all be ( BS ) taught of God .’ Everyone who has heard and learned from the Father, comes to Me. 46 ( BT ) Not that anyone has seen the Father, except the One who is from God; He has seen the Father. 47 Truly, truly, I say to you, he who believes ( BU ) has eternal life. 48 ( BV ) I am the bread of life. 49 ( BW ) Your fathers ate the manna in the wilderness, and they died. 50 This is the bread which ( BX ) comes down out of heaven, so that one may eat of it and ( BY ) not die. 51 ( BZ ) I am the living bread that ( CA ) came down out of heaven; if anyone eats of this bread, ( CB ) he will live forever; and the bread also which I will give ( CC ) for the life of the world is ( CD ) My flesh.”
52 ( CE ) Then the Jews ( CF ) began to argue with one another, saying, “How can this man give us His flesh to eat?” 53 So Jesus said to them, “Truly, truly, I say to you, unless you eat the flesh of ( CG ) the Son of Man and drink His blood, you have no life in yourselves. 54 He who eats My flesh and drinks My blood has eternal life, and I will ( CH ) raise him up on the last day. 55 For My flesh is true food, and My blood is true drink. 56 He who eats My flesh and drinks My blood ( CI ) abides in Me, and I in him. 57 As the ( CJ ) living Father ( CK ) sent Me, and I live because of the Father, so he who eats Me, he also will live because of Me. 58 This is the bread which ( CL ) came down out of heaven; not as ( CM ) the fathers ate and died; he who eats this bread ( CN ) will live forever.”