A.T. Robertson 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)

When day was now breaking (πρωιας ηδη γινομενης). Genitive absolute and note present middle participle (dawn coming on and still dark). In Mt 27:1 the aorist participle (γενομενης) means that dawn had come. For "beach" (αιγιαλον) see Mt 13:2.

Was (εστιν). Present indicative retained in indirect assertion.