It appears by this that God revealed himself by dreams (which evidenced themselves to be divine and supernatural) not only to his servants the prophets, but even to those who were out of the pale of the church and covenant; but then, usually, it was with some regard to God's own people as in Pharaoh's dream, to Joseph, in Nebuchadnezzar's, to Daniel, and here, in Abimelech's, to Abraham and Sarah, for he reproved this king for their sake, Psa 105:14, Psa 105:15.
I. God gives him notice of his danger (Gen 20:3), his danger of sin, telling him that the woman is a man's wife, so that if he take her he will wrong her husband; his danger of death for this sin: Thou art a dead man; and God's saying so of a man makes him so. Note, Every wilful sinner ought to be told that he is a dead man, as the condemned malefactor, and the patient whose disease is mortal, are said to be so. If thou art a bad man, certainly thou art a dead man.
II. He pleads ignorance that Abraham and Sarah had agreed to impose upon him, and not to let him know that they were any more than brother and sister, Gen 20:6. See what confidence a man may have towards God when his heart condemns him not, Jo1 3:21. If our consciences witness to our integrity, and that, however we may have been cheated into a snare, we have not knowingly and wittingly sinned against God, it will be our rejoicing in the day of evil. He pleads with God as Abraham had done, Gen 18:23. Wilt thou slay a righteous nation? Gen 20:4. Not such a nation as Sodom, which was indeed justly destroyed, but a nation which, in this matter, was innocent.
III. God gives a very full answer to what he had said.
1. He allows his plea, and admits that what he did he did in the integrity of his heart: Yea, I know it, Gen 20:6. Note, It is matter of comfort to those that are honest that God knows their honesty, and will acknowledge it, though perhaps men that are prejudiced against them either cannot be convinced of it or will not own that they are.
2. He lets him know that he was kept from proceeding in the sin merely by the good hand of God upon him: I withheld thee from sinning against me. Abimelech was hereby kept from doing wrong, Abraham from suffering wrong, and Sarah from both. Note, (1.) There is a great deal of sin devised and designed that is never executed. As bad as things are in the world, they are not so bad as the devil and wicked men would have them. (2.) It is God that restrains men from doing the ill they would do. It is not from him that there is sin, but it is from him that there is not more sin, either by his influence upon men's minds, checking their inclination to sin, or by his providence, taking away the opportunity to sin. (3.) It is a great mercy to be hindered from committing sin; of this God must have the glory, whoever is the instrument, Sa1 25:32, Sa1 25:33.
3. He charges him to make restitution: Now therefore, not that thou art better informed, restore the man his wife, Gen 20:7. Note, Ignorance will excuse no longer than it continues. If we have entered upon a wrong course through ignorance this will not excuse our knowingly persisting in it, Lev 5:3-5. The reasons why he must be just and kind to Abraham are, (1.) Because he is a prophet, near and dear to God, for whom God does in a particular manner concern himself. God highly resents the injuries done to his prophets, and takes them as done to himself. (2.) Being a prophet, he shall pray for thee; this is a prophet's reward, and a good reward it is. It is intimated that there was great efficacy in the prayers of a prophet, and that good men should be ready to help those with their prayers that stand in need of them, and should make, at least, this return for the kindnesses that are done them. Abraham was accessory to Abimelech's trouble, and therefore was obliged in justice to pray for him. (3.) It is at thy peril if thou do not restore her: Know thou that thou shalt surely die. Note, He that does wrong, whoever he is, prince or peasant, shall certainly receive for the wrong which he has done, unless he repent and make restitution, Col 3:25. No injustice can be made passable with God, no, not by Caesar's image stamped upon it.

In the integrity of my heart, etc. - Had Abimelech any other than honorable views in taking Sarah, he could not have justified himself thus to his Maker; and that these views were of the most honorable kind, God himself, to whom the appeal was made, asserts in the most direct manner, Yea, I know that thou didst this in the integrity of thy heart.

And God said unto him in a dream,.... The same dream continued:

yea, or "also"

I know that thou didst this in the integrity of thy heart; not only thou knowest, but I, who know all things, know and acknowledge that this was so done by thee. Abimelech's plea is admitted, and a very great testimony borne to his integrity in this matter; and throughout the whole account he appears to be a man of great honour and uprightness, especially in this affair, if not a good man:

for I also withheld thee from sinning against me; for had he committed adultery with her, it had been not only a sin against her, and against her husband, but against God being contrary to his will revealed in the minds of men by the law and light of nature, before the law of Moses was given: and indeed all sin against the neighbour is ultimately against God, see Psa 51:4; and now from the commission of this sin God restrained Abimelech, either by some impulse upon his mind not to take her to be his wife as yet, or by throwing some thing or other in the way of it, in his providence, or by inflicting some disease upon him, which rendered him incapable of it, Gen 20:17,

therefore suffered I thee not to touch her; that is, to have carnal knowledge of her, see Co1 7:1; as there is nothing done but what is done by divine permission, so many more evils would be committed than there are, were it not that men are restrained from them by the power and providence of God, not suffering them to do them; and in particular this sin was prevented, that it might not in any respect be a doubtful point whether Isaac, whom Sarah had now conceived, was a legitimate son of Abraham; and these expressions of Abimelech not coming near her, Gen 20:4; and not touching her as here, are used for that purpose.

But God came to Abimelech in a dream--In early times a dream was often made the medium of communicating important truths; and this method was adopted for the preservation of Sarah.