“And Yitzchak Was Comforted After His Mother”
The Torah relates: “And Yitzchak brought her into the tent of Sarah his mother, and he took Rivkah, and she became his wife, and he loved her; and Yitzchak was comforted after his mother.” (Bereishis 24:67)
Rashi comments on the words “after his mother”: “This teaches us the way of the world: As long as a person’s mother is alive, he remains attached to her; once she passes away, he finds comfort in his wife.”
This seems difficult. For in Parshas Bereishis (2:24), the Torah states: “Therefore a man shall leave his father and his mother and cleave to his wife, and they shall become one flesh.” If so, why does Rashi teach us here that as long as a person’s mother is alive, he remains attached to her? Surely, once a man marries, he has already left his father and mother and cleaves to his wife!
Maran HaGaon Rav Chaim Kanievsky zt”l explained that, indeed, when a person marries, he leaves his father and mother and cleaves to his wife. It is with her that he establishes his home and builds his family; his soul becomes bound to hers, and his love and devotion are directed toward her.
Nevertheless, he remains obligated in the mitzvah of honoring his mother, for he is still bound to honor and revere her, and to assist her with all her needs insofar as the laws of kibbud eim require. Therefore, his soul still remains connected to his mother to a certain degree.
However, after his mother passes away, his soul becomes entirely bound to his wife, and it is in her that he finds his comfort and tranquility of spirit.
This is precisely what Rashi means when he says, “Once she passes away, he finds comfort in his wife.” There is therefore no contradiction whatsoever between the words of Rashi here and the verse in Parshas Bereishis.