Haydock's Catholic Bible Commentary: Matthew
Ver. 18. Why could not we? The disciples began to apprehend that they had incurred their Master's displeasure, and had thereby lost their power of working miracles. They come therefore secretly to Jesus Christ, to learn why they could not cast out devils. He answered them, that it was their want of faith, which probably failed them on this occasion, on account of the difficulty of the cure, little reflecting that the virtue of the Lord, which worked in them, was superior to every possible evil of both mind and body. --- St. Hilary is of opinion, that during the absence of Christ on the mountain, the fervour of the apostles had begun to abate. (Jansenius)
Ver. 19. If you have faith as a grain of mustard-seed. Christ insinuates to his apostles, as if they had not yet faith enough to work great miracles, which require a firm faith joined with a lively confidence in God. The mustard-seed is brought in with an allusion to its hot and active qualities. (Witham) --- That is, a perfect faith; which, in its properties and its fruits, resembles the grain of mustard-seed in the parable. (Chap. xii.[xiii.?] 31.) (Challoner) --- By faith is here understood, not that virtue by which we assent to all things that are to be believed of Christ, the first, of the theological virtues, in which the apostles were not deficient, but that confidence in the power and goodness of God, that he will on such an occasion exert these, his attributes, in favour of the supplicant. To have a true faith of this kind, and free from all presumption, is a great and high privilege, which the Holy Ghost breathes into such only as he pleases. (Jansenius) --- Examples of this efficacious faith are given by St. Paul. (Hebrews chap. ii.[xi.?]) St. Gregory of Neo-Cæsarea is also related, by Eusebius and Ven. Bede, to have removed by the efficacy of his faith a rock, which obstructed the building of a church; thus literally fulfilling the promise of Jesus Christ. (Tirinus) --- The faith of the apostles, especially of those that had not been present at the transfiguration, was not perfect and complete in all its parts, till after the resurrection and ascension of Jesus Christ, and the descent of the Holy Ghost. (Haydock) --- St. Jerome understands by mountains, things the most difficult to be effected.
Ver. 20. See here the efficacy of prayer and fasting! What the apostles could not do, prayer accompanied with fasting can effect. How then can that be genuine religion, which makes fasting an object of ridicule? We see also here that the true Church in her exorcisms follows Scripture, when she uses besides the name of Jesus, many prayers and much fasting to drive out the devils, because these, as well as faith, are here required. (Bristow)
Ver. 21. Jesus then taking the road to Jerusalem with his disciples, and whilst they were in Galilee, which they had to pass through, he spake to them of his sufferings, death, and resurrection. (Bible de Vence)
Ver. 22. They were troubled exceedingly, not being able to comprehend the mystery of Christ's sufferings and death, which were so opposite to the notions they had of the glorious kingdom of the Messias. (Witham) --- This grief was the consequence of their attachment to their divine Master. They were ignorant, as St. Mark and St. Luke notice, of the word that was spoken. They full well understood that he would be put to death, but did not sufficiently comprehend the shortness of his rest in the grave, the nature of his triumphant resurrection, nor the inestimable benefits which his death would bring on the world. (St. Chrysostom, hom. lix.)
Ver. 23. They that received the didrachmas, (ta didrachma) in value about fifteen-pence of our money. (Witham) --- A tax, according to some, laid on every person who was twenty years of age, for the service of the temple. See Exodus xxx. St. Chrysostom thinks it was paid for the first-born only, whom the Lord would have redeemed for the first-born of the Egyptians, whom he slew. Others think it was a tribute paid to the Romans, as Christ, in ver. 24, seems to insinuate, by mentioning the kings of the earth; and the Jews were tributary to them at this time. In ver. 24, the evangelist uses the word Kensos, taken from the Latin census, or tax.
Ver. 25. Then the children. From these words and the following, that we may not scandalize them, some argue that Christians are exempt from taxes. The fallacy of this deduction is victoriously demonstrated from the express words of St. Paul, (Romans xiii.) commanding us to be subject to the higher powers, not only for wrath, but also for conscience sake: Render tribute to whom tribute is due; custom to whom custom, &c. The word children then does not mean subjects, but must be understood in its natural limited sense. (Jansenius) --- Jesus Christ argues a minori ad majus thus, if the kings of the earth exact money from their subjects only, and exempt their own children, how much more ought I to be exempt, who do not claim my descent from a temporal prince only, but from the supreme King of heaven. This example our Saviour would never have adduced, says St. Chrysostom had he not really been the Son of God. (hom. lix.) Our Saviour uniformly waved his right to exemptions in temporal things: he declares every where that temporal princes have nothing to fear from him, or his doctrines, since his kingdom is not of this world. (Haydock)
Ver. 26. But that we may not. Jesus Christ pays the tribute, not as one subject to the law, but as consulting the infirmity of the people; but he first shews himself exempt from the above example, lest his disciples might take occasion of scandal therefrom. (St. Chrysostom, hom. lix.) --- For me and thee. A great mystery this: Jesus Christ paid not only for himself, but for the future representative of Him and his Church, in whom, as chief, the rest were comprised. (St. Augustine, q. ex Nov. Tes. q. lxxv. tom. 4.) Jesus Christ here, as well as on many other occasions, pointedly marks the precedence of Peter, which might give rise to the strife and contention of the disciples, in the commencement of the ensuing chapter, on the subject of superiority. Thus St. Jerome, St. Chrysostom, Tirinus, &c.
Bible Text & Cross-references:
The transfiguration of Christ: He cures the lunatic child, foretells his passion: and pays the didrachma.
1 And *after six days Jesus taketh unto him Peter and James, and John his brother, and bringeth them up into a high mountain apart:
2 And he was transfigured before them. And his face did shine as the sun: and his garments became white as snow.
3 And behold there appeared to them Moses and Elias, talking with him.
4 Then Peter answering, said to Jesus: Lord, it is good for us to be here: if thou wilt, let us make here three tabernacles, one for thee, and one for Moses, and one for Elias.
5 And as he was yet speaking, behold a bright cloud overshadowed them. *And behold a voice out of the cloud, saying: This is my beloved Son, in whom I am well pleased: hear ye him.
6 And the disciples hearing, fell upon their face, and were very much afraid.
7 And Jesus came and touched them: and said to them: Arise, and be not afraid.
8 And lifting up their eyes, they saw no man but only Jesus.
9 And as they came down from the mountain, Jesus charged them, saying: Tell the vision to no man, till the Son of man be risen from the dead.
10 And his disciples asked him, saying: *Why then do the Scribes say that Elias must come first?
11 But *he answering, said to them: Elias indeed shall come, and restore all things.
12 But I say to you, *that Elias is already come, and they knew him not, **but have done unto him whatsoever they had a mind. So also the Son of man shall suffer from them.
13 Then the disciples understood that he had spoken to them of John the Baptist.
14 *And when he was come to the multitude, there came to him a man falling down on his knees before him, saying: Lord, have pity on my son, for he is a lunatic, and suffereth much: for he falleth often into the fire, and often into the water.
15 And I brought him to thy disciples, and they could not cure him.
16 Then Jesus answered, and said: O unbelieving and perverse generation, how long shall I be with you? how long shall I suffer you? Bring him hither to me.
17 And Jesus rebuked him, and the devil went out of him, and the child was cured from that hour.
18 Then came the disciples to Jesus secretly, and said: Why could not we cast him out?
19 Jesus said to them: Because of your unbelief. *For amen I say to you, if you have faith as a grain of mustard-seed, you shall say to this mountain: Remove from hence to yonder place, and it shall remove, and nothing shall be impossible to you.
20 But this kind is not cast out but by prayer and fasting.
21 And while they abode together in Galilee, Jesus said to them: *The Son of man shall be betrayed into the hands of men:
22 And they shall kill him, and the third day he shall rise again. And they were troubled exceedingly.
23 And when they were come to Capharnaum, they that received the didrachmas, came to Peter, and said to him: Doth not your master pay the didrachma?
24 He said: Yes. And when he was come into the house, Jesus prevented him, saying: What is thy opinion, Simon? Of whom do the kings of the earth receive tribute or custom? of their own children, or of strangers?
25 And he said: Of strangers. Jesus said to him: Then the children are free.
26 But that we may not scandalize them, go thou to the sea, and cast in a hook: and that fish which shall first come up, take: and when thou hast opened its mouth, thou shalt find a stater: take that, and give it to them for me and thee.
____________________
*
1: about the year A.D. 32.; Mark ix. 1.; Luke ix. 28.
5: Matthew iii. 17.; 2 Peter i. 17.
10: Mark ix. 10.
11: Malachias iv. 5.
12: Matthew xi. 14. --- ** Matthew xiv. 10.
14: Mark ix. 16.; Luke ix. 38.
19: Luke xvii. 6.
21: Matthew xx. 18.; Mark ix. 30.; Luke ix. 44.