And Jesus answering, said unto them,.... Knowing that they aimed at him; though, according to this evangelist, they only mentioned his disciples, however, he takes up the cause, and vindicates both himself and them, by observing to them the following proverb;

they that are whole need not a physician, but they that are sick: suggesting hereby, that as such who are in good health, who are free from all diseases, wounds, bruises, and putrefying sores, stand in no need of the advice and assistance of a physician, or surgeon, but such who have either distempers or sores on their bodies; so they, the Scribes and Pharisees, who, in their own opinion, were free from the disease of sin, original and actual, and touching the righteousness of the law, were blameless, stood not in any need of him, the physician, who came to cure the maladies of the souls, as well as of the bodies of men; but such persons, who not only are sick with sin, but sick of it, who are sensible of it, and desire healing: and therefore this was the reason of his conduct, why he conversed with sinners, and not with the Scribes and Pharisees; his business, as a physician, lying among the one, and not the other; See Gill on Matthew 9:12. See Gill on Mark 2:17.

They that are whole (οἱ ὑγιαίνοντες)

Both Matthew and Mark use ἰσχύοντες, the strong. This use of the verb in its primary sense, to be in sound health, is found in Luke 7:10; Luke 15:27; and once in John, 3 Ep. 3 John 1:2. For this meaning it is the regular word in medical writings. Paul uses it only in the metaphorical sense: sound doctrine, sound words, sound in faith, etc. See 1 Timothy 1:10; 1 Timothy 6:3; Titus 1:13, etc.

And Jesus answering said unto them, They that are whole need not a physician; but they that are sick.

5:27-39 It was a wonder of Christ's grace, that he would call a publican to be his disciple and follower. It was a wonder of his grace, that the call was made so effectual. It was a wonder of his grace, that he came to call sinners to repentance, and to assure them of pardon. It was a wonder of his grace, that he so patiently bore the contradiction of sinners against himself and his disciples. It was a wonder of his grace, that he fixed the services of his disciples according to their strength and standing. The Lord trains up his people gradually for the trials allotted them; we should copy his example in dealing with the weak in faith, or the tempted believer.