Matthew 9:14

He then having stopped their mouths every way, as well from the Scriptures as from the natural consequence of things; and they having nothing to say, proved as they were obnoxious to the charges which they had brought against Him, and adversaries of the law and the Old Testament; they leave Him, and again transfer their accusation to the disciples. And Luke indeed affirms that the Pharisees said it, but this evangelist, that it was the disciples of John; but it is likely that both said it. That is, they being, as might be expected, in utter perplexity, take the other sort with them; as they did afterwards with the Herodians likewise. Since in truth John's disciples were always disposed to be jealous of Him, and reasoned against Him: being then only humbled, when first John abode in the prison. They came at least then, "and told Jesus;" but afterwards they returned to their former envy. Now what say they? "Why do we and the Pharisees fast oft, but thy disciples fast not?" This is the disease, which Christ long before was eradicating, in the words, "When thou fastest, anoint thy head, and wash thy face;" foreknowing the evils that spring therefrom. But yet He doth not rebuke even these, nor say, "O ye vainglorious and over-busy;" but He discourses to them with all gentleness.

O boastful enquiry and ostentation of fasting much to be blamed, nor can John's disciples be excused for their taking part with the Pharisees who they knew had been condemned by John, and for bringing a false accusation against Him whom they knew their master had preached.

(ubi sup.) Though Matthew mentions only the disciples of John as having made this enquiry, the words of Mark rather seem to imply that some other persons spoke of others, that is, the guests spoke concerning the disciples of John and the Pharisees—this is still more evident from Luke; why then does Matthew here say, Then came unto him the disciples of John, (Luck 5:33.) unless that they were there among other guests, all of whom with one consent put this objection to Him?

For John drank neither wine, nor strong drink, increasing his merit by abstinence, because he had no power over nature. But the Lord who has power to forgive sins, why should He shun sinners that eat, since He has power to make them more righteous than those that eat not? Yet doth Christ fast, that you should not avoid the command; but He eats with sinners that you may know His grace and power.

(ap. Anselm.) When He had replied to them respecting eating and converse with sinners, they next assault Him on the matter of food; Then came to him the disciples of John, saying, Why do we and the Pharisees fast often, but thy disciples fast not?