Matthew Henry's Concise Commentary on the Bible - John 6:47-51
47-51 The advantage of the manna was small, it only referred to this life; but the living Bread is so excellent, that the man who feedeth on it shall never die. This bread is Christ's human nature, which he took to present to the Father, as a sacrifice for the sins of the world; to purchase all things pertaining to life and godliness, for sinners of every nation, who repent and believe in him. read more
George Haydock's Catholic Bible Commentary - John 6:51
Christ now no longer calls the belief in him, or the preaching of the gospel, the bread that he will give them; but he declares that it is his own flesh, and that flesh which shall be given for the life of the world. (Calmet) --- This bread Christ then gave, when he gave the mystery of his body and blood to his disciples. (Ven. Bede) read more