Is it lawful to cure on Sabbath? The meaning of this question is, ought the curing of a man to be reckoned among the works which violate the Sabbath? If they had said that the observance of the Sabbath is violated in this way, the reply was obvious, that it is a work of God. Now the law of the Sabbath goes no farther, than that men shall rest from their own works. Christ first puts the question to them, and he does so for the purpose of guarding against offense. It would not have been necessary for him to pacify them, if they had not been instigated by hardened malice. Not that he always laid himself under this restriction; for in many cases he did what had been enjoined on him by the Father, without attending to the offense that might arise from it. But he intended to show by this example, that he did not inconsiderately perform miracles on Sabbath, because he was prepared to assign a reason for what he did. They, on the other hand, make it evident by their silence, that their desire of finding fault is stronger than their zeal for the law; and therefore Christ treats with utter indifference their opinion about his action, because it was evident that they intentionally sought out an occasion of offense.

Jesus, answering - To "answer," in the Scriptures, does not always imply, as among us, that anything had been said before. It means often merely to "begin" or to take up a subject, or, as here, to remark on the case that was present.
Is it lawful - He knew that they were watching him. If he healed the man at once, they would accuse him. He, therefore, proposed the question to them, and when it was asked, they could not say that it was not lawful.

And Jesus answering, spake unto the lawyers and Pharisees,.... All the Oriental versions, for "lawyers", read "Scribes": these, with the Pharisees, were got together in a body, in their brother Pharisee's house, to watch the motions of Christ; who knew their designs upon him, and the thoughts of their hearts, and made answer to them, by putting the following question;
saying, is it lawful to heal on the sabbath day? The occasion of the question was the object before him, whom Christ had a compassionate regard to, and determined to cure; but knowing that these men were catching at every thing, to traduce him, was desirous of having their sentiments first; not but that he knew full well, what was agreeable to the law of God, and what was not; and what also were the traditions of their elders, which they held, and which allowed of healing on the sabbath day, where life was in danger.

(See on Matthew 12:11-12).

And Jesus answering, spake - Answering the thoughts which he saw rising in their hearts.