5 For to the Gentiles He went not Himself, but sent His disciples. And in this was fulfilled what the Prophet said; “A people whom I have not known has served Me.” See how deep, how clear, how express the prophecy is; “a people whom I have not known,” that is, to whom I have not exhibited My Presence, “has served Me.” How? It goes on to say, “By the hearing of the ear they have obeyed Me:” that is, they have believed, not by seeing, but by hearing. Therefore have the Gentiles the greater praise. For the others saw and slew Him; the Gentiles heard and believed. Now it was to call and gather together the Gentiles, that that might be fulfilled which we have just now chanted, “Gather us from among the Gentiles, that we may confess to Your Name, and glory in Your praise,” that the Apostle Paul was sent. He, the least, made great, not by himself, but by Him whom he once persecuted, was sent to the Gentiles, from a robber become a shepherd, from a wolf a sheep. He, the least Apostle, was sent to the Gentiles, and laboured much among the Gentiles, and through him the Gentiles believed. His Epistles are the witnesses.
Source: Sermons on Selected Lessons of the New Testament (New Advent)