John Calvin Commentary Matthew 20:30

"And behold, two blind men sitting by the way side, when they heard that Jesus was passing by, cried out, saying, Lord, have mercy on us, thou son of David." — Matthew 20:30 (ASV)

Have mercy on me, O Lord. I stated, a short time ago, that there was at first but one who cried out, but the other was induced by a similar necessity to join him. They confer on Christ no ordinary honor when they request him to have mercy and relieve them; for they must have been convinced that he had in his power the assistance or remedy they needed.

But their faith is still more clearly exhibited by their acknowledgment of him as Messiah, to whom we know that the Jews gave this designation, Son of David. They therefore apply to Christ, not only as some Prophet, but as that person whom God had promised to be the only Author of salvation.

The cry proved the ardor of the desire; for, though they knew that what they said exposed them to the hatred of many, who were highly displeased with the honor done to Christ, their fear was overcome by the ardor of desire, so that they did not refrain, for this reason, from raising their voice aloud.