Luke 18:39

Why then did the blind man, on hearing that He was passing by, exclaim, "Jesus, Thou Son of David, have mercy on me? " unless he was considered, in no uncertain manner, to be the Son of David (in other words, to belong to David's family) through his mother and his brethren, who at some time or other had been made known to him by public notoriety? "Those, however, who went before rebuked the blind man, that he should hold his peace."

They were trying to prevent him, fearing that his eyes may be opened, and the Pharisees might recognize him and be irritated.

The blind man must have understood that the sight of the blind cannot be restored by human means but requires, on the contrary, a divine power and an authority such as God only possesses. With God nothing whatsoever is impossible. The blind man came near to him as to the omnipotent God. How then does he call him the Son of David? What can one answer to this? The following is perhaps the explanation. Since he was born and raised in Judaism, of course, the predictions contained in the law and the holy prophets concerning Christ had not escaped his knowledge. He heard them chant that passage in the book of the Psalms, "The Lord has sworn in truth to David, and will not annul it, saying: 'of the fruit of your loins I will set a king upon your throne.' " The blind man also knew that the blessed prophet Isaiah said, "There will spring up a shoot from the root of Jesse, and from his root a flower will grow up." Isaiah also said, "Behold, a virgin will conceive and bring forth a son, and they will call his name Emmanuel, which being interpreted is, God with us." He already believed that the Word, being God, of his own will had submitted to be born in the flesh of the holy Virgin. He now comes near to him as to God and says, "Have mercy on me, Son of David." Christ testifies that this was his state of mind in offering his petition. He said to him, "Your faith has saved you."

And since the imaginations of things, which ought to lead us to God, present an obstacle to our prayer, therefore he adds: And those who went before rebuked him, that he should be silent. Whence the Gloss: "Those who go before Jesus as he comes …

Those who precede Jesus as he comes—what do they signify but the crowds of carnal desires and the tumults of vices, which, before Jesus comes to our heart, scatter our thoughts with their temptations and disturb the voice of the heart in prayer? For often when we wish to turn to the Lord after committing sins, when we strive to pray against those very vices we have committed, the phantoms of the sins we have done rush upon the heart, strike back against the vision of our mind, confuse the soul, and suppress the voice of our entreaty. Those who went before, therefore, were rebuking him to be silent, because before Jesus comes to the heart, the evils we have done, thrust upon our thoughts through their images, disturb us in the very midst of our prayer. But let us hear what this blind man who was to be illuminated did in response to these things. It follows: "But he cried out all the more: Son of David, have mercy on me." Behold, the one whom the crowd rebukes to be silent cries out more and more, because the more heavily we are pressed by the tumult of carnal thoughts, the more ardently we ought to persist in prayer. The crowd opposes us lest we cry out, because we often suffer the phantoms of our sins even in prayer. But indeed it is necessary that the voice of our heart insist all the more strongly the more harshly it is repelled, so that it may overcome the tumult of unlawful thought and burst forth to the merciful ears of the Lord by the excess of its importunity. Each one, as I suspect, recognizes in himself what we are saying, because when we turn our mind from this world to God, when we turn to the work of prayer, the very things we previously did with delight we afterward endure as troublesome and burdensome in our prayer. […]