The writer composed chapter 20 as another chiasm with the focal point being Abimelech warning his servants (v. 8). Two dialogues dominate the story: the one between God and Abimelech (vv. 3-7) and the one between Abimelech and Abraham (vv. 9-13).
"The focus of the narrative of chapters 20 and 21 is on the relationship between Abraham and the nations. Abraham's role is that of a prophetic intercessor, as in the promise all peoples on earth will be blessed through you' (12:3). He prayed for the Philistines (20:7), and God healed them (v. 17). In the narrative Abimelech plays the role of a righteous Gentile' with whom Abraham could live in peace and blessing. There is, then, an implied contrast in the narratives between chapters 19 (Lot, the one who pictures the mixed multitude) and 20 (Abimelech, the righteous sojourner)."552
Abraham lied about his relationship with Sarah again (cf. ch. 12). Abimelech took her into his harem as a consequence of the patriarch's deception. Nevertheless God intervened to preserve Sarah's purity. He warned Abimelech to restore Sarah to her husband, to make restitution to Abraham, and to ask Abraham the prophet to intercede with God for him.
This chapter records another crisis in the story of God's providing an heir for Abraham.
"Apparently, shortly after the announcement of a birth one year hence, Sarah is again taken into another man's harem. The reader is to infer that if there is an heir, he is in danger of being reckoned as Abimelech's not Abraham's. But Yahweh intervenes once again and preserves Sarah (20.6b) and restores her to Abraham."553
". . . the episode is chiefly one of suspense: on the brink of Isaac's birth-story here is the very Promise put in jeopardy, traded away for personal safety. If it is ever to be fulfilled, it will owe very little to man. Morally as well as physically, it will clearly have to be achieved by the grace of God."554
Abraham naturally moved frequently since he had to find pasture for his flocks and herds (v. 1). He lived a semi-nomadic life.
". . . his house and family remained at Gerar while he was down in Sinai . . ."555
"Abimelech"was a title rather than a proper name (cf. 26:1; Judg. 8:31; 1 Sam. 21:10; Ps. 34 title). It meant "royal father"or "the king [Milku, a Canaanite deity mentioned in the Amarna letters] is my father."556
Dreams were one of the primary means by which God revealed Himself to individuals in the Old Testament along with visions and personal encounters (cf. 15:1; Num. 12:6-8). Adultery commonly drew the death penalty in the ancient Near East, which the Mosaic Code later reflected (Lev. 20:10; Deut. 22:22). Abimelech claimed to head a blameless nation (v. 4), so we expect God to be gracious since Abraham had prayed that the Lord would not destroy the righteous with the wicked (18:23-32). God was gracious with Abimelech and his people (v. 6).
Moses identified Abraham here (v. 7) as a "prophet."This is the first explicit reference to a prophet in the Old Testament. Prophets received direct revelations from God and spoke to others for God. Here the role of the prophet includes that of intercessor, as it does elsewhere in Scripture.
"In king Abimelech we meet with a totally different character from that of Pharaoh [ch. 12]. We see in him a heathen imbued with a moral consciousness of right, and open to receive divine revelation, of which there is not the slightest trace in the king of Egypt."557
"Like the sailors and the king of Nineveh in the book of Jonah (1:16; 3:6-9), the Philistines responded quickly and decisively to God's warning. Like Jonah, however, Abraham in this narrative was a reluctant prophet."558
Fear for his safety evidently led Abraham to act as he did even though his experience with Pharaoh in Egypt had been unsuccessful. Even the repeated promises of God did not drive fear of potential danger from Abraham's heart. God used a pagan king to rebuke the righteous prophet, who had boldly pleaded for Sodom, when Abraham's faith failed.
This incident shows God's faithfulness to Abraham compared to Abraham's unfaithfulness to God (cf. 2 Tim. 2:13). God's chosen ones cannot destroy His ultimate plans for them by failing. Abraham learned that Yahweh can maintain His covenant and fulfill His promises in spite of the opposition and interference of influential and powerful individuals.
God requires His people to maintain purity in marriage and to look to Him to provide what He has promised.
