For it is written (gegraptai gar). Luke here returns to the address of Peter interrupted by Act 1:18, Act 1:19. Perfect passive indicative, the usual idiom in quoting scripture, stands written. Ps 69 is often quoted as Messianic in Matthew and John.
His habitation (hē epaulis autou). Only here in the N.T., a country house, cottage, cabin.
His office (tēn episkopēn autou). Our word bishopric (Authorized Version) is from this word, office of bishop (episcopos). Only that is not the idea here, but over-seership (epi, skopeō) or office as in 1Pe 2:12. It means to visit and to inspect, to look over. The ecclesiastical sense comes later (1Ti 3:1).