A.T. Robertson Commentary John 21:1

"After these things Jesus manifested himself again to the disciples at the sea of Tiberias; and he manifested [himself] on this wise." — John 21:1 (ASV)

Manifested himself (εφανεροσεν εαυτον). First aorist active indicative of φανεροω with the reflexive pronoun (cf. 7:4; 13:4). For the passive see 1:31; 21:14. Jesus was only seen during the forty days now and then (Acts 1:3), ten instances being recorded. The word φανεροω is often used of Christ on earth (John 1:31; John 2:11; 1 Peter 1:20; 1 John 1:2), of his works (John 3:5), of the second coming (1 John 2:28), of Christ in glory (Colossians 3:4; 1 John 3:2).

At (επ). By or upon.

Of Tiberias (της Τιβεριαδος). As in 6:1 instead of the usual "Sea of Galilee." Tiberias, the capital city of Galilee, gave this epithet to the Sea of Galilee. This is not the appearance in Galilee prearranged by Jesus (Matthew 28:7,16).