So when (οτε ουν). Transitional use of ουν, sequence, not consequence.

Received him (εδεξαντο αυτον). First aorist middle of δεχομα, "welcomed him." Jesus had evidently anticipated a quiet arrival.

Having seen (εωρακοτες). Perfect active participle of οραω. Note θεωρουντες in John 2:23 about this very thing at the feast in Jerusalem. The miracles of Jesus at that first passover made a stir.

For they also went (κα αυτο γαρ ηλθον). The Samaritans did not go and so Jesus was a new figure to them, but the Galileans, as orthodox Jews, did go and so were predisposed in his favour.