In which way are Mishkav and Moshav more stringent than Maga?
Rashi: Whereas the former become an Av ha'Tum'ah15 which is Metamei Adam and the clothes he is wearing, the latter only becomes a Rishon, which is only Metamei food and drink. 1
See also Sifsei Chachamim.
What are the implications of "ve'Ish asher Yiga ... "?
Sifra: It implies that Adam who touches a Mishkav or Moshav is subject to Kibus Begadim, but not one Mishkav which touches another Mishkav. 1
See Torah Temimah, note 22.
Why does the Torah write "asher Yiga' with refard to Mishkav, and "ve'ha'Yoshev ... " with regard to Moshev?
Oznayim la'Torah: Because a person generally makes his bed before lying down on it ? in which case he inevitably touches it, whereas he sits on a chair without prior preparations. 1
Oznayim la'Torah: As far as Tum'as Mishkav and Moshav are concerned however, they share exactly the same Din.
Why does the Torah write "ve'Ish asher Yiga" (in the future - whereas in Pasuk 7 it writes "ve'ha'Noge'a" ? in the present)?
Sifra: To teach us that he only renders Tamei the clothes that he is wearing whilst he is touching the Mishkav or the Moshav, but not those that he puts on afterwards. 1
Because Adam ve'Keilim can only receive Tum'ah from an Av ha'Tum'ah, but not from a Toldah.
Why does the Torah write "ve'Ish asher Yiga be'Mishkavo" and not "asher Yiga bahem"?
Shabbos, 84a: To compare the Mishkav of the Zav to the Zav, inasmuch as just as he becomes Tahor by Toveling in a Mikvah, so too does his Mishkav.
Bava Kama, 66b: To Darshen "be'Mishkavo", 've'Lo ha'Gazul' ? to preclude a stolen Mishkav from the Din of Tum'as Mishkav, since it only becomes a Rishon le'Tum'ah. 1
Sifra: To Darshen that if the Mishkav breaks it is no longer considered a Mishkav.
Sifra: It precludes a rope that remains after it has been woven into the bed-frame that is less than five Tefachim or more than ten, and threads that protrude from the knot that are less than three finger-breadths. 2
