What are the connotations of "Va'yish'alu ... le'Ishto"?
Rashi and Targum Yonasan: It means that they asked (not his wife, but) about his wife'. 1
Ha'amek Davar: They asked (Malbim - also) his wife.
Rashi: Like we find in Vayeira, 20:13 ?Imri Li Achi Hu?.
When Yitzchak told them that Rivkah was his sister, why did they not question him about the children (Ya?akov and Eisav)?
Ramban: Because, as far as they were concerned, they may well have been somebody else's children. 1
They could even have been his sister's or his own children ? but not Rivkah?s.
Why was he afraid lest they kill him due to Rivkah?
Malbim: He suspected everyone, because [all] "Anshei ha'Makom" asked about her, and they also asked her herself.
Why didn't Yitzchak tell her to say that she is his sister, like Avraham told Sarah?
Ha'amek Davar: He did not need to, for she was exceedingly reverent of Yitzchak, and would never do anything against his desire, as explained above (refer to 24:62:1:7*).
Why was Yitzchak afraid? HaSh-m had told him, "v'Ehyeh Imcha" (26:3)?
