The connection and meaning of this passage are very interesting. The Lord had just been teaching the solemnity of being a cause of stumbling to one of His “little ones,” and that, to avoid this, we must take heed to ourselves, so that we may never be weary of forgiving our brother if he trespasses against us. Rebuke him we may, and should; but if he repents, he is instantly to be forgiven; and if he trespass against us seven times a day, and says on each occasion, “I repent,” forgiveness is never to be wanting. This is grace. God never wearies in forgiving us when we confess our sins, and we, as exponents of His heart, are to exhibit the same readiness to forgive the sins of our brother. (Compare Matthew 18:21,22) The apostles evidently failed to comprehend the far-reaching character of this instruction, and yet as evidently felt their need of something more than they had hitherto received if they were to carry it out in practice. They thus interposed with the prayer, “Lord, increase our faith.” In answer to this, the Lord, while graciously recognizing the need that turned to Him, reminds them that it is not so much a question of the increase of their faith, as the exercise of what they already possessed.
“If,” He says, “ye had faith as a grain of mustard seed, ye might say unto this sycamore tree, be thou plucked up by the root, and be thou planted in the sea; and it should obey you.” Now a mustard seed is the “least of all seeds” (Matthew 13:32); and consequently our Lord teaches that all the power of God is linked with the exercise of the smallest degree of faith; that faith, be it small or be it great, takes hold upon omnipotent power; and hence it is that “all things are possible to him that believeth.” The father, for example, who cried, “Lord, I believe, help thou mine unbelief,” received the answer in the healing of his child, equally with the centurion whose faith surpassed that of any in Israel. (Mark 9:24; Luke 7:7-9) E. D.