Genesis 20:8

Abimelech carried out the divine instructions. The next morning he collected his servants together and related what had occurred, at which the men were greatly alarmed. He then sent for Abraham, and complained most bitterly of his conduct, by which he had brought a great sin upon him and his kingdom.

Abimelech, being thus warned of God in a dream, takes the warning, and, as one truly afraid of sin and its consequences, he rises early to obey the directions given him. I. He has a caution for his servants, Gen 20:8. Abraham himself could not be more careful than he was to command his household in this matter. Note, Those whom God has convinced of sin and danger ought to tell others what God has done for their souls, that they also may be awakened and brought to a like holy fear. II. He has a chiding for Abraham. Observe, 1. The serious reproof which Abimelech gave to Abraham, Gen 20:9, Gen 20:10. His reasoning with Abraham upon this occasion was very strong, and yet very mild. Nothing could be said better; he does not reproach him, nor insult over him, does not say, "Is this your profession? I see, though you will not swear, you will lie. If these be prophets, I will beg to be freed from the sight of them:" but he fairly represents the injury Abraham had done him, and calmly signifies his resentment of it. (1.) He calls that sin which he now found he had been in danger of a great sin. Note, Even the light of nature teaches men that the sin of adultery is a very great sin: be it observed, to the shame of many who call themselves Christians, and yet make a light matter of it. (2.) He looks upon it that both himself and his kingdom would have been exposed to the wrath of God if he had been guilty of this sin, though ignorantly. Note, The sins of kings often prove the plagues of kingdoms; rulers should therefore, for their people's sake, dread sin. (3.) He charges Abraham with doing that which was not justifiable, in disowning his marriage. This he speaks of justly, and yet tenderly; he does not call him a liar and cheat, but tells him he had done deeds that ought not to…

20:8-10 Abraham had earned rebukes from Abimelech and from God (cp. 12:17-19). Abimelech was angry that Abraham’s deception had made him guilty of this great sin (see study note on 20:3-7). He knew that taking a married woman into his harem was wrong.