Luke 18:42

(Chrys. ut sup.) Or because the Jews perverting the truth might say, as in the case of him who was born blind, This is not he, but one like unto to him, (John 9:8.) He wished the blind first to make manifest the infirmity of his nature, that then he might fully acknowledge the greatness of the grace bestowed upon him. And as soon as the blind man explained the nature of his request, with words of the highest authority He commanded him to see. As it follows, And Jesus said to him, Receive thy sight. This served only still more to increase the guilt of unbelief in the Jews. For what prophet ever spoke in this way? Observe moreover what the physician claims from him whom he has restored to health. Thy faith hath saved thee. For faith then mercies are sold. Where faith is willing to accept, there grace abounds. And as from the same fountain some in small vessels draw little water, while others in large draw much, the fountain knowing no difference in measure; and as according to the windows which are opened, the sun sheds more or less of its brightness within; so according to the measure of a man's motives does he draw down supplies of grace. The voice of Christ is changed into the light of the afflicted. For He was the Word of true light.

(ubi sup.) Well then was it said to the blind, Receive thy sight; thy faith hath saved thee.

And to show that our Lord did not even walk without doing good, He performed a miracle on the way, giving His disciples this example, that we should be profitable in all things, and that nothing in us should be in vain.