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
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"
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"?