Seeing as both Shem and Yefes took the blanket and covered their father, why does the Torah write "And he took" in the singular?
Rashi: Shem alone was the prime mover; 1 he took the initiative. Therefore, descendants of Shem merited a Talis of Tzitzis, 2 Gog (from Yefes) merited burial, while the descendants of Cham would be exiled unclothed.
He made more effort than Yefes, and, as the Mishnah says in Pirkei Avos (at the end of the fifth Perek) "The reward is commensurate with the effort."
Riva: This refers to a nice garment. (Avraham is credited by Chazal with the merit of the Mitzvah of the Tzitzis themselves; refer to 9:23:1.3:3). Also, when Chananya, Misha'el and Azaryah were cast into the fiery furnace, they were cast in fully clothed (Daniel 3:21), in Shem's merit. Likewise, the sons of Aharon were consumed by fire, but their clothes remained intact (Vayikra 10: 2,5), in the merit of Shem (Da'as Zekenim to 9:25).
Why does the Torah repeat the fact that Shem and Yefes faced the other way?
Rashi and Seforno: To teach us that, even when they came close to their father and had to turn around in order to cover him, they kept their faces turned away from him.
QUESTIONS ON RASHI
Rashi writes: "Shem's descendants merited the Talis of Tzitzis, Yefes merited burial for his descendants, whereas Cham... young and old were led out bare and exposed into exile." How was this Midah k'Neged Midah for each of the sons?
Gur Aryeh: Shem and Yefes restored the honor of their father by covering him, so they too deserved a covering of honor. Because Shem exerted himself more, he merited the Talis, which is a Mitzvah, and covers a living person (Guf and Neshamah). Yefes merited a burial, which is honor for the body alone. Cham disgraced the Guf, and so was done unto him.
Rashi writes: "Shem merited... the Talis, Yefes merited burial... whereas Cham... was exiled bare and exposed." Why did each of the three act in such a manner, and how does their recompense match with their essence?
Gur Aryeh: Yefes (lit. "beauty"), is a characteristic of the Guf. The body's nature is sluggish, and so Yefes acted; therefore only the Guf of his descendents would receive honor through burial. Cham (lit. "hot") represents the Nefesh, the life-force represented by natural heat and physicality; therefore, he was cursed to be a slave. 1 Shem (lit. "name") represents the essence, the Tzurah that a person can attain, and so his reward involves a Mitzvah. 2
Gur Aryeh: It is not the body itself that is negative, but the pursuing of bodily physicality.
Gur Aryeh adds that the three sons of Noach parallel the three sons of Adam ha'Rishon: Yefes represents Hevel, for "beauty is futile" (Mishlei 31:30; Cham represents Kayin, for he too was cursed (4:11); and Shem represents Sheis, lit. "foundation," upon which the world would be built.
Rashi writes: "Shem's descendants merited the Talis of Tzitzis." However, the Gemara (Sotah 17a) attributes this merit to Avraham, who said, "If even a thread or shoelace..." (14:23).
Moshav Zekenim: Avraham's merit clarified which descendants of Shem would receive Mitzvas Tzitzis.
Mizrachi: The Talis with white Tzitzis is in the merit of Shem, while the Techeiles string of the Tzitzis is in the merit of Avraham.
Gur Aryeh: Both share the merit; the Talis garment itself is in the merit of Shem [who spread a garment], and the strings are in the merit of Avraham.
