{Twelve years old} (et(936e) d(9364)eka). Predicate genitive. Luke
does not say that Jesus had not been to Jerusalem before, but at
twelve a Jewish boy became a "son of the law" and began to
observe the ordinances, putting on the phylacteries as a
reminder. {They went up} (anabainont(936e) aut(936e)). Genitive
absolute with present active participle, a loose construction
here, for the incident narrated took place _after_ they had gone
up, not _while_ they were gong up. "On their usual going up"
(Plummer).