Increase our faith - This duty of forgiving offences seemed so difficult to the disciples that they strongly felt the need of an increase of faith. They felt that they were prone themselves to harbor resentments, and that it required an additional increase of true religion to enable them to comply with the requirements of Jesus. We may learn from this:
1. That Jesus has "the power" of increasing the faith of his people. Strength comes from him, and especially strength to believe the gospel. Hence, he is called the "Author and Finisher" of our faith, Hebrews 12:2.
2. The duty of forgiving offences is one of the most difficult duties of the Christian religion. It is so contrary to our natural feelings; it implies such elevation above the petty feelings of malice and revenge, and is so contrary to the received maxims of the world, which teach us to "cherish" rather than to forgive the memory of offences, that it is no wonder our Saviour dwells much on this duty, and so strenuously insists on it in order to our having evidence that our hearts have been changed.
Some have thought that this prayer that he would increase their faith refers to the power of working miracles, and especially to the case recorded in Matthew 17:16-20.

Increase our faith - This work of pardoning every offense of every man, and that continually, seemed so difficult, even to the disciples themselves, that they saw, without an extraordinary degree of faith, they should never be able to keep this command. But some think that this and what follows relate to what Matthew has mentioned. Matthew 17:19, Matthew 17:20.

(3) And the apostles said unto the Lord, Increase our faith.
(3) God will never be utterly lacking to the godly (although he may not be as thorough with them as they wish) even in those difficulties which cannot be overcome by man's reason.

And the apostles said unto the Lord,.... Either on account of what was now said by Christ concerning offences, and forgiving injuries; being conscious to themselves of their own weakness to withstand temptations; and fearful lest they should be stumbled and offended with what they should meet with; or that they should give offence to others: and being also sensible of what spirits they were of, and of the difficulties of conquering them, and mastering the resentment of their minds, when injured and provoked; and also the necessity of divine assistance, of having fresh supplies of grace, and of having their graces, and particularly faith, strengthened, and drawn into a lively exercise; or on account of their not being able to cast out a devil from one that was possessed, Matthew 17:19 when words, to the same purpose, were spoken by Christ, as in the following verse; on occasion of one or other of these, though more likely the former, the apostles addressed Christ in this manner,
increase our faith; both the faith of working miracles, and the grace of believing in him: by which, as they express their sense of the weakness, and imperfection of their faith; and their great desire to have it increased, which might be for their comfort, and his glory; so they acknowledge his divine power, and that he is the author and finisher of faith; and that as the beginning, so the increase of it is from him: wherefore faith is not of a man's self, or the produce of man's freewill and power, but is the gift of God; and even where it is, it is not in man to increase it, or add to it, or to draw it forth into exercise; this also is the operation of God. And if the apostles had need to put up such a petition to Christ, much more reason have other men.

Lord--(See on Luke 10:1).
increase our faith--moved by the difficulty of avoiding and forgiving "offenses." This is the only instance in which a spiritual operation upon their souls was solicited of Christ by the Twelve; but a kindred and higher prayer had been offered before, by one with far fewer opportunities. (See on Mark 9:24.)

Increase our faith. They desire more faith. In the face of the overwhelming odds against them, the general unbelief, and the fact that Jesus would not be the kind of a Christ that they and all the Jews had expected, they felt the need of more faith.
As a grain of mustard seed. See notes on Matthew 13:32.
Sycamine tree. A species of the fig.
It should obey you. See notes on Mark 11:22-26.

Lord, increase our faith - That we may thus forgive, and may neither offend nor be offended. Matthew 17:20.