Matthew Henry Commentary John 6:47-51

"Verily, verily, I say unto you, He that believeth hath eternal life. I am the bread of life. Your fathers ate the manna in the wilderness, and they died. This is the bread which cometh down out of heaven, that a man may eat thereof, and not die. I am the living bread which came down out of heaven: if any man eat of this bread, he shall live for ever: yea and the bread which I will give is my flesh, for the life of the world." — John 6:47-51 (ASV)

The advantage of the manna was small; it only referred to this life. But the living Bread is so excellent that the person who feeds 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, and to purchase all things pertaining to life and godliness for sinners of every nation who repent and believe in Him.