Luke 2:43

43andκαὶhaving completedτελειωσάντωνtheτὰςdaysἡμέρας,inἐνtheτῷreturningὑποστρέφεινof themαὐτοὺςremained behindὑπέμεινενJesusἸησοῦςtheὁboyπαῖςinἐνJerusalemἸερουσαλήμ,Butκαὶnotοὐκknewἔγνωσανtheοἱparentsγονεῖςof Himαὐτοῦ.

and having completed the days, in their returning, the boy Jesus remained behind in Jerusalem, and His parents did not know.