Albert Barnes on Luke 13:23

Then said one. Who this was does not appear. It is probable that he was not one of the disciples, but one of the Jews, who came either to perplex him, or to involve him in a controversy with the Pharisees.

Are there few that be saved? It was the prevalent opinion among the Jews that few would enter heaven. As but two of all the hosts that came out of Egypt entered into the land of Canaan, so some of them maintained that a proportionally small number would enter into heaven (Lightfoot). On this subject the man wished the Opinion of Jesus. It was a question of idle curiosity. The answer to it would have done little good. It was far more important for the man to secure his own salvation, than to indulge in such idle inquiries and vain speculations. Our Lord therefore advised him, as he does all, to strive to enter into heaven.