Luke 17:6

If ye had faith as a grain of mustard seed. — The words remind us, and must have reminded the disciples, of those of Matthew 17:20, which were called forth by the failure of the disciples to heal the demoniac boy after the Transfiguration. The “sycamine tree” (probably not the same as the “sycamore,” but identified by most botanists with the mulberry tree, still cultivated on the slopes of the Lebanon and in the neighbourhood of Jerusalem and Nablous, both for its fruit and as supplying food for silkworms) takes the place of “this mountain,” sc. Hermon, as an illustration of what true faith could do. If we suppose the conversation to have taken place near the Sea of Galilee, both features of the comparison gain a local vividness. It is remarkable that our Lord meets the prayer with what sounds like a reproof; and such a reproof, we must believe, was needed. The most elementary faith would have been enough to teach them (assuming the connection that has been traced above) that God is love, and that He would help them to overcome all hindrances to their love being after the pattern of His own. There was something, it may be, false in the ring of that prayer, an unreal diffidence asking for that as a gift which really comes only through active obedience and the experience which is gained through it.