And when His disciples James and John saw it. The country itself had perhaps suggested to them the desire of thundering immediately against the ungodly; for it was there that Elijah had formerly destroyed, by a fire from heaven, the king's soldiers who had been sent to apprehend him, (2 Kings 1:10.) It therefore occurred to them that the Samaritans, who so basely rejected the Son of God, were at that time devoted to a similar destruction. And here we see to what we are driven by a foolish imitation [1] of the holy fathers. James and John plead the example of Elijah, but they do not consider how far they differ from Elijah; they do not examine properly their own intemperate zeal, nor do they look at the calling of God. Under a pretext equally plausible did the Samaritans cloak their idolatry, our fathers worshipped in this mountain, (John 4:20.) But both were in the wrong; for, neglecting the exercise of judgment, they were apes rather than imitators of the holy fathers. Now though it is doubtful whether they think that they have the power in their own hand, or ask Christ to give it to them, I think it more probable that, elated with foolish confidence, they entertain no doubt that they are able to execute vengeance, provided that Christ give his consent.

Footnotes

1 - "Une folle et inconsideree imitation des saincts peres;" -- "a foolish and ill-considered imitation of the holy fathers."

James and John - They were called Boanerges - sons of thunder - probably on account of their energy and power in preaching the gospel, or of their vehement and rash zeal - a remarkable example of which we have in this instance, Mark 3:17.
Wilt thou - The insult had been offered to Jesus, their friend, and they felt it; but their zeal was rash and their spirit bad. Vengeance belongs to God: it was not theirs to attempt it.
Fire from heaven - Lightning, to consume them.
As Elias did - By this they wished to justify their zeal. Perhaps, while they were speaking, they saw Jesus look at them with disapprobation, and to vindicate themselves they referred to the case of Elijah. The case is recorded in 2-Kings 1:10-12.

That we command fire - Vengeance belongs to the Lord. What we suffer for his sake, should be left to himself to reprove or punish. The insult is offered to him, not to us. See the note on Mark 3:17.

(12) And when his disciples James and John saw [this], they said, Lord, wilt thou that we command fire to come down from heaven, and consume them, even as Elias did?
(12) We must take heed of zeal and fond imitation which is not moderated, even in good causes, that whatever we do, we do it to God's glory, and the profit of our neighbour.

And when his disciples, James and John, saw this,.... The Persic version reads thus; when "James and John, and the disciples saw this"; that is, the other disciples besides them, so making all the disciples say what follows; whereas only those two are intended, who having been the messengers, were the more provoked at this indignity to their Lord and master:
they said, Lord, wilt thou that we command fire to come down from heaven, and consume them; being enraged at this conduct of the Samaritans towards, Christ, and burning with love to him, and zeal for his honour; being "Boanerges's", sons of thunder, they were for punishing of them in a most terrible manner, even with, fire from heaven; by which Sodom and Gomorrah, and the cities of the plain, were destroyed: this they doubted not of doing, knowing what miraculous power was conferred upon them; but did not think proper to attempt to exert it, until they had asked leave of Christ to do it:
even as Elias did; upon the two captains of fifties, with their fifties, as recorded in 2-Kings 1:9 This clause was wanting in a certain copy of Beza's, and is not in the Vulgate Latin version; but is in other copies and versions, and by all means to be retained.

James and John--not Peter, as we should have expected, but those "sons of thunder" (Mark 3:17), who afterwards wanted to have all the highest honors of the Kingdom to themselves, and the younger of whom had been rebuked already for his exclusiveness (Luke 9:49-50). Yet this was "the disciple whom Jesus loved," while the other willingly drank of His Lord's bitter cup. (See on Mark 10:38-40; and Acts 12:2). That same fiery zeal, in a mellowed and hallowed form, in the beloved disciple, we find in 1-John 5:10; 3-John 1:10.
fire . . . as Elias--a plausible case, occurring also in Samaria (2-Kings 1:10-12).

As Elisha did - At or near this very place, which might put it into the minds of the apostles to make the motion now, rather than at any other time or place, where Christ had received the like affront.