but by fasting and prayer: that is, in the exercise of a miraculous faith, expressed in solemn prayer to God, joined with fasting. It seems that Christ not only suggests, that faith was greatly wanting in his disciples; for which reason they could not cast out the devil, and heal the lunatic; but they had been wanting in prayer to God, to assist them in the exercise of their miraculous gifts; and that whilst Christ, and the other three disciples were on the mount, they had been feasting and indulging themselves with the people, and so were in a very undue disposition of mind, for such extraordinary service, for which our Lord tacitly rebukes them. This agrees with the notions of the Jews, who think that, by fasting, a divine soul (f) , "may obtain that which is sought for"; and that among other things, for which a private person may afflict himself with fasting, this is one, , "because of an evil spirit" (g); which they think may be got rid of this way.
(f) Jacchiades in Dan. x. 3.((g) T. Bab. Taanith, fol. 22. 2. Maimon. Hilch. Taaniot, c. 1. sect. 6.