Jesus stood still. He acknowledged the title of "Son of David," and, as the blind men could not follow him, he stopped his progress; their perseverance won his acceptance; he was ready to listen to their appeal and to grant their request.
Called them. The gracious summons left them in no doubt as to the happy issue of their prayer. St. Mark speaks of the joyful alacrity with which the blind man obeyed the call; how he "cast away his garment, sprang up, and came to Jesus."
What will ye that I shall do unto you? The Lord knew the desire of their hearts, but he wished to draw forth the public confession of their needs, and the distinct blessing which they craved, that all the bystanders might acknowledge the miracle, and the sufferers themselves might be incited more vehemently to urge their plea, and thus become more worthy of relief.
So God knows all our necessities before we ask, but he will have our prayers, that we may cooperate with him in the work which he purposes to accomplish.