Ge 26:7 And the men of the place asked about his wife. And he said, "She is my sister"; for he was afraid to say, "She is my wife," because he thought, "lest the men of the place kill me for Rebekah, because she is beautiful to behold."

8 Now it came to pass, when he had been there a long time, that Abimelech king of the Philistines looked through a window, and saw, and there was Isaac, showing endearment to Rebekah his wife.

9 Then Abimelech called Isaac and said, "Quite obviously she is your wife; so how could you say, 'She is my sister'?" And Isaac said to him, "Because I said, 'Lest I die on account of her.'"

10 And Abimelech said, "What is this you have done to us? One of the people might soon have lain with your wife, and you would have brought guilt on us."

11 So Abimelech charged all his people, saying, "He who touches this man or his wife shall surely be put to death."

12 Then Isaac sowed in that land, and reaped in the same year a hundredfold; and the LORD blessed him.

13 The man began to prosper, and continued prospering until he became very prosperous;

14 for he had possessions of flocks and possessions of herds and a great number of servants. So the Philistines envied him.

The whole point of these verses is this---Moses is highlighting God's faithfulness to his Israelite readers through the life of their forefather Isaac. Back in verse 3, God assured Isaac: "Dwell in this land, and I will be with you and bless you..."

Moses intentionally recounted the parallel events of Abraham's life and Isaac's life to show that in both lives God was faithful. The point is this----"He could be just as faithful to you Israelites who are their descendants."

This should encourage them to be faithful to God in response and not turn to other gods.