{I go a fishing} (hupag(9320)halieuein). The present active
infinitive halieuein expresses purpose as often. It is a late
verb from halieus (fisherman) and occurs in  Jer 16:16 , in
Philo, Plutarch, and one papyrus. Peter's proposal was a natural
one. He had been a fisherman by practice and they were probably
waiting in Galilee for the appointed meeting with Christ on the
mountain. Andrew and Peter, James and John were fishermen also.
Peter's proposition met a ready response from all. {They took}
(epiasan). First aorist active indicative of piaz(935c), Doric
form for piez(935c), to catch.