Upon arriving in Gerar, Isaac faces a dangerous situation that closely mirrors the trials of his father. Finding himself a stranger in a new place with a beautiful wife, he uses a clever strategy to protect his life, though the exact circumstances and his methods differ from those of Abraham.
When the local men begin asking questions, the primary approach among commentators is that they direct their inquiries to Isaac about his wife. However, another perspective suggests the neighbors approach Rebecca directly. According to this view, the locals hope she will reveal the truth out of fear of being taken, knowing Isaac might lie to avoid being killed. To prevent her from answering and exposing their secret, Isaac quickly speaks up in her place [אלשיך, מלבי״ם, פרדס יוסף].
By claiming she is his sister, Isaac relies on the fact that Rebecca is indeed a close relative. This makes his story believable, a claim likely supported by their physical resemblance [ביאור יש״ר, שטיינזלץ]. Unlike his father, who instructed his wife beforehand on how to present herself, Isaac does not coordinate this plan with Rebecca. He simply trusts her completely, knowing she is deeply devoted to him and will not contradict his words [העמק דבר]. As for how Isaac conceals the fact that they are parents to twin boys, the locals simply never ask. Had they inquired, Isaac is prepared to claim that the boys are his sons from another woman [רמב״ן, הטור הארוך].
Isaac's actions are driven by a deep, internal fear for his life [אבן עזרא]. He is specifically terrified of the local mob rather than King Abimelech, since his father had previously established a peace treaty with the king [אלשיך]. Isaac's vulnerability contrasts with Abraham's situation; Abraham had intimidated the region after defeating the kings and therefore did not fear identifying himself as a married man, whereas Isaac lacks this intimidating reputation and genuinely fears for his survival [חזקוני]. By adopting his father's exact line of thought and expressing his fears personally, Isaac fully absorbs his father's mindset [חומת אנך].
Rebecca is noted for her beauty, though the description of her appearance is slightly less intense than in her youth, reflecting the fact that she has already given birth to her sons [חזקוני]. Yet, despite her beauty, she is not immediately taken to the royal palace as Sarah once was. The local people have learned a harsh lesson from the plagues they suffered during Abraham's time. They are now extremely careful to avoid harming a married woman or taking any woman from this particular family [חזקוני, ביאור יש״ר, שטיינזלץ].