When he was come back again (en tōi epanelthein auton). “On the coming back again as to him.” Luke’s favourite idiom of the articular infinitive after en and with the accusative of general reference.
Had given (dedōkei). Past perfect active indicative without augment of didōmi.
That he might know (hina gnoi). Second aorist active subjunctive of ginoskō. The optative would be gnoiē.