And when the disciples saw it. This also is not unusual with the Evangelists, when a thing has been done by one, to attribute it to many persons, if they give their consent to it. John says that the murmur proceeded from Judas, who betrayed Christ, (John 12:4.) Matthew and Mark include all the disciples along with him. The reason is, that none of the others would ever have dared to murmur if the wicked slander of Judas had not served for a torch to kindle them. But when he began, under a plausible pretext, to condemn the expense as superfluous, all of them easily caught the contagion. And this example shows what danger arises from malignant and envenomed tongues; for even those who are naturally reasonable, and candid, and modest, if they do not exercise prudence and caution, are easily deceived by unfavorable speeches, and led to adopt false judgments. But if light and foolish credulity induced the disciples of Christ to take part with Judas, what shall become of us, if we are too easy in admitting murmurers, who are in the habit of carping wickedly at the best actions? We ought to draw from it another warning, not to pronounce rashly on a matter which is not sufficiently known. The disciples seize on what Judas said, and, as it has some show of plausibility, they are too harsh in forming a judgment. They ought, on the contrary, to have inquired more fully if the action deserved reproof; more especially when their Master was present, by whose decision it was their duty to abide. Let us know, therefore, that we act improperly, when we form our opinion without paying regard to the word of God; for, as Paul informs us, None of us liveth or dieth to himself, but all must stand before the judgment-seat of Christ, where we must give our account, (Romans 14:7, 10; 2-Corinthians 5:10.) And though there was a wide difference between Judas and the others -- because he wickedly held out a plausible cloak for his theft, while the rest were actuated by foolish simplicity -- still we see how their imprudence withdrew them from Christ, and made them the companions of Judas.

They had indignation - John says that "Judas expressed" indignation.
Probably some of the others felt indignation, but Judas only gave vent to his feelings. The reason why Judas was indignant was, that he had the "bag" John 12:6 - that is, the "purse," or repository of articles "given" to the disciples and to the Saviour. He was a thief, and was in the habit, it seems, of taking out and appropriating to his own use what was put in for them in common The leading trait of Judas's character was avarice, and no opportunity was suffered to pass without attempting by base and wicked means to make money. In his example an avaricious man may learn the true nature and the effect of that groveling and wicked passion. It led him to commit the enormous crime of betraying his Lord to death, and it will always lead its possessor to guilt. No small part of the sins of the world can be traced to avarice, and many, and many a time since the days of Judas has the Lord Jesus been betrayed among his professed friends by the same base propensity.
Is this waste - This "loss" or "destruction" of property. They could see no use in it, and they therefore supposed it was lost.

His disciples - One of them, viz. Judas. This mode of speaking was common among the Hebrews. So, Matthew 27:44, the thieves also, i.e. one of them. So, Matthew 28:17, some doubted, i.e. one, Thomas. See also Genesis 8:4; Judges 12:7; Nehemiah 6:7, etc. By a figure called among rhetoricians enallag, the plural is put for the singular; it is, however, possible that Judas, who made the objection, was followed in the sentiment by the rest of the disciples.

But when his (d) disciples saw [it], they had indignation, saying, To what purpose [is] this (e) waste?
(d) This is a figure of speech called synecdoche: for it is said that only Judas was moved at this; (John 12:4).
(e) Unprofitable spending.

But when his disciples saw it,.... What the woman did, what a costly box of ointment it was, and with what profusion she used it,
they had indignation: Mark says, "within themselves", Mark 14:4; either among themselves, or their indignation was secret in their breasts; their resentment was private, though it might be betrayed by their looks, and afterwards showed itself in words. This indignation was either at the woman, for the Evangelist Mark observes, that "they murmured against her", Mark 14:5, that she should act such an imprudent part, and be guilty of such extravagance; or at Christ himself, for suffering such an action to be done unto him; for so the Syriac version reads the above clause in Mark, and "they murmured against him"; so De Dieu observes it should be rendered; though Tremellius, Boderianus, and others, translate it, "against her": or else their indignation was neither at Christ, whom they dearly loved; nor at the woman, they being taught to love their enemies, and much more the friends of Christ; but at the action, which they looked upon as an ill judged thing, that sprung from misguided zeal, and which they thought could never be acceptable to their master, who was not used to encourage such profuseness and extravagance.
Saying, to what purpose is this waste, or "loss?" They call that waste, or loss, which was spent on Christ himself; whereas, whatever is laid out for the honour of Christ, or the good of his interest, ought not to be reckoned loss, for it will be returned with great increase and advantage; but they could not see what end was to be answered by this expense. It is easy to observe the variableness and inconstancy of the disciples: one time, because the inhabitants of a certain village did not receive Christ, they were for calling for fire from heaven to destroy them; and here is a poor woman that exceeds, as they thought, in her respects to him, and they are filled with indignation.

They had indignation. John shows that it was Judas who voiced the indignation.
Why this waste? Judas thought that 300 pence had been squandered. Sordid men still often think what is spent for the Savior is wasted.

His disciples seeing it, had indignation, saying - It seems several of them were angry, and spoke, though none so warmly as Judas Iscariot.