D-R Bible, Haydock Commentary:
Ver. 11. He that is the lesser, &c. Many understand this of Christ, who is less in as much as he is more humble, younger in age, and according to the erroneous opinion of men, of less sanctity than John. Maldonatus and Tolletus suppose the meaning to be, that he who is the least in sanctity in the Church of Christ is greater than John; not that John did not excel in sanctity many, nay even most of the children of the Church of Christ, but that those who belong to the Church, on account of this circumstance of their being under the new law, which is the law of children, are greater than those under the old law, which was the law of bondsmen, as the least among the children is greater than the greatest among the bondsmen. Now John in this respect did not belong to the Church of Christ, as he was slain before Christ’s death, before which time the gospel was not fully established. (Menochius) — There hath not risen … a greater, &c. This comparison, by what we find, Luke vii. 28, is only betwixt John and the ancient prophets, to signify that John was greater than any of the prophets, at least by his office of being the immediate precursor of the Messias. The comparison cannot be extended to Christ himself, who was both God and man, nor to his blessed Virgin Mother; nor need we understand it of his apostles. (Witham)
Ver. 12. Suffereth violence, &c. It is not to be obtained but by main force, by using violence upon ourselves, by mortification and penance, and resisting our perverse inclinations. (Challoner) — Certainly it is great violence for a man to look for a seat in heaven, and to obtain that by his virtue which was refused him by his nature. (St. Jerome in St. Thomas Aquinas) — The kingdom of heaven, &c. That is, the kingdom of heaven is to be obtained by mortification, penance, poverty, and those practices of austerity which John, both by word and example, pointed out. According to this interpretation, the kingdom of heaven means eternal life. Or the meaning may be, the kingdom of heaven is taken by the violent, because it is not now confined, as in the old law, to one people, but open to all, that whoever will may enter in and take possession of it. The kingdom of heaven, in this interpretation, is taken for the Church of Christ, for the gospel, and also for eternal life. (Menochius)