3 

3:28 We conclude then that a man is justified by faith - And even by this, not as it is a work, but as it receives Christ;and, consequently, has something essentially different from all our works whatsoever.

3:29 Surely of the gentiles also - As both nature and the scriptures show.

3:30 Seeing it is one God who - Shows mercy to both, and by the very same means.

3:31 We establish the law - Both the authority, purity, and the end of it; by defending that which the law attests; by pointing out Christ, the end of it; and by showing how it may be fulfilled in its purity.

4 Having proved it by argument, he now proves by example, and such example as must have greater weight with the Jews than any other.

1. That justification is by faith:
2. That it is free for the gentiles.

4:1 That our father Abraham hath found - Acceptance with God.According to the flesh - That is, by works.

4:2 The meaning is, If Abraham had been justified by works, he would have had room to glory. But he had not room to glory. Therefore he was not justified by works.

4:3 Abraham believed God - That promise of God concerning the numerousness of his seed, Gen 15:5, Gen 15:7; but especially the promise concerning Christ, Gen 12:3, through whom all nations should be blessed. And it was imputed to him for righteousness - God accepted him as if he had been altogether righteous. Gen 15:6.

7 Our Lord now proceeds to warn us against the chief hinderances of holiness. And how wisely does he begin with judging? wherein all young converts are so apt to spend that zeal which is given them for better purposes.

7:24  Luk 6:47.

7:29 He taught them - The multitudes, as one having authority - With a dignity and majesty peculiar to himself as the great Lawgiver, and with the demonstration and power of the Spirit: and not as the scribes - Who only expounded the law of another; and that in a lifeless, ineffectual manner.

8 

8:2 A leper came - Leprosies in those countries were seldom curable by natural means, any more than palsies or lunacy.Probably this leper, though he might not mix with the people, had heard our Lord at a distance. Mar 1:40; Luk 5:12.

8:4 See thou tell no man - Perhaps our Lord only meant here, Not till thou hast showed thyself to the priest - who was appointed to inquire into the case of leprosy. But many others he commanded, absolutely, to tell none of tho miracles he had wrought upon them. And this he seems to have done, chiefly for one or more of these reasons:

1. To prevent the multitude from thronging him, in the manner related Mar 1:45.
2. To fulfil the prophecy, Isa 42:1, that he would not be vain or ostentatious. This reason St. Matthew assigns, Mat 12:17, etc
3. To avoid the being taken by force and made a king, Joh 6:15. And,
4. That he might not enrage the chief priests, scribes, and Pharisees, who were the most bitter against him, any more than was unavoidable, Mat 16:20-21.

For a testimony - That I am the Messiah; to them - The priests, who otherwise might have pleaded want of evidence. Lev 14:2.