Jesus said unto them,
Come and dine.
And none of the disciples dared ask him, Who are you? knowing that it was the Lord.
All Commentaries on John 21:12 Go To John 21
John Chrysostom
AD 407
John does not say that He ate with them, but Luke does. He ate however not to satisfy the wants of nature, but to show the reality of His resurrection.
He means that they had not confidence to talk to Him, as before, but sat looking at Him in silence and awe, absorbed in regarding His altered and now supernatural form, and unwilling to ask any question. Knowing that it was the Lord, they were in fear, and only ate what, in exercise of His great power, He had created. He again does not look up to heaven, or do anything after a human sort, thus strewing that His former acts of that kind were done only in condescension: Jesus then comes, and takes bread, and gives them, and fish likewise.
Inasmuch, however, as He did not converse with them regularly, or in the same way as before, the Evangelist adds, This is now the third time that Jesus showed Himself to His disciples, after that He was risen from the dead.