Jamieson, Fausset and Brown on Matthew 9:27

27. And when Jesus departed thence, two blind men followed him--hearing, doubtless, as in a later case is expressed, "that Jesus passed by" (Mt 20:30).

crying, and saying, Thou son of David, have mercy on us--It is remarkable that in the only other recorded case in which the blind applied to Jesus for their sight, and obtained it, they addressed Him, over and over again, by this one Messianic title, so well known--"Son of David" (Mt 20:30). Can there be a doubt that their faith fastened on such great Messianic promises as this, "Then the eyes of the blind shall be opened," &c. (Is 35:5)? and if so, this appeal to Him, as the Consolation of Israel, to do His predicted office, would fall with great weight upon the ears of Jesus.