Genesis 26:8
And it came to pass, when he had been there a long time, that Abimelech king of the Philistines looked out at a window, and saw, and, behold, Isaac was sporting with Rebekah his wife.
Cross-references
Genesis 21:32
Historical context
Genesis 21:32 records Abimelek returning to Philistine territory after his treaty with Abraham — he reappears here observing Isaac.