Charles Ellicott Commentary John 21:4

"But when day was now breaking, Jesus stood on the beach: yet the disciples knew not that it was Jesus." — John 21:4 (ASV)

Jesus stood on the shore.—Compare to John 20:19; John 20:26. The words express the sudden appearance without any indication of His coming. He was then standing in the midst, or on the shore, but no one knew from where or how.

The disciples did not know that it was Jesus.—Compare to John 20:14.