What does Genesis 26:7 mean?Isaac is walking in Abraham's footsteps, seemingly for better or worse. Like Abraham, he obeyed the Lord by settling down in Gerar (Genesis 26:1–5). Like Abraham, he will interact with a king named Abimelech, in the land of the Philistines (Genesis 22:21–24). And now, like Abraham, he will lie about his beautiful wife being his sister out of fear of someone killing him to take her.
This scenario is slightly different than what Abraham did with Sarah in Egypt (Genesis 12:10–20) and then later in Gerar (Genesis 20:1–18). For one thing, Abraham seemed to have planned further ahead, asking Sarah to participate in his lie before telling it to others. Second, Abraham's wife Sarah was, technically, his half-sister, giving the lie the sheen of truthfulness.
This verse reads almost as if Isaac spewed it out in the heat of the moment in response to some men asking about his wife. He may have had actual cause to be concerned about his safety. In his case, though, Rebekah was not by any measure his sister (Genesis 22:20–23).
Interestingly, neither Abraham nor Isaac are condemned for their action in the text itself—in fact, God protects them both, along with their wives. This is challenging, since the lie seems especially unloving and weak. Worse, it comes immediately following God's promise in the previous verses to be with Isaac and to bless him. Was this strategy, handed down from father to son, a demonstration of a lack of faith in God? God has reiterated His blessings so that Isaac knows they apply to him, personally (Genesis 26:3–4). Perhaps God is allowing Isaac to learn that his trust in God must be personal, as well.