Theophylact of Ohrid
Catena Aurea · Johannesevangelium 6
Then said they unto him, What shall we do, that we might work the works of God? Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent. They said therefore unto him, What sign shewest thou then, that we may see, and believe thee? what dost thou work? Our fathers did eat manna in the desert; as it is written, He gave them bread from heaven to eat. Then said Jesus unto them, Verily, verily, I say unto you, Moses gave you not that bread from heaven; but my Father giveth you the true bread from heaven. For the bread of God is he which cometh down from heaven, and giveth life unto the world. Then said they unto him, Lord, evermore give us this bread.
But this bread, being essentially life, (for He is the Son of the living Father,) in quickening all things, does but what is natural to Him to do. For as natural bread supports our weak flesh, so Christ, by the operations of the Spirit, gives life to the soul; and even incorruption to the body, (for at the resurrection the body will be made incorruptible.) Wherefore He says, that He giveth life unto the world.