Why does the Torah write "Ish Ish"?
Torah Temimah (citing Toras Kohanim): To teach us that, even if the Shochet did not actually hunt the bird but purchased it, inherited it or received it as a gift, he is nevertheless obligated to cover its blood.
Targum Yonasan: Refer to 17:3:1:1*.
Why does the Pasuk insert the word "Tzeid", after it already said "Yatzud"?
Rashi (from Chulin 84a): To include the obligation to cover the blood of chickens and geese, even though they do not need to be caught.
What does "Asher Ye'achel" come to preclude?
Rashi: It comes to preclude Tamei species from the Mitzvah.
Targum Yonasan: It comes to preclude birds and Chayos that became Neveilos via an improper Shechitah.
Why does the blood of Chayos and birds require covering?
Ibn Ezra, Moshav Zekenim: We should not think that it is blood of a Korban to idolatry. 3
Ralbag: It is lest one come to eat it. In the Midbar there was no concern for Dam Behemah, for they were permitted only as Shelamim. Later, when Basar Ta'avah was permitted, Yisrael were already distanced from the lowly habit of eating blood (so the Torah did not add a Chiyuv to cover Dam Behemah, but the Chiyuv remains for blood of Chayos and birds. - PF)
Rashi writes that we must cover the blood even of species that need not be hunted. If so, why does it say "Yatzud"?
Rashi (from Chulin 84a): This teaches that one should eat meat only in such a case. 1
Rashi 84a, Sifsei Chachamim: He should not regularly eat meat, lest he become poor. Moshav Zekenim - he should eat only from his toil, or alternatively, only when it is cheap.
If he slaughters more than one, must he cover each separately?
Moshav Zekenim: "Chayah" implies even many, and so does "Ohf"; one covering suffices for many. 1
Chulin 6:3. If he slaughtered a Chayah and a bird, Chachamim say, one covering suffices; R. Yehudah says, he covers Dam ha'Chayah, and afterwards slaughters the bird.
Why does it say "be'Afar", and not 'Afsar'?
Moshav Zekenim: (citing Chulin 83b): This teaches that one must put earth below the blood and on top. 1
Moshav Zekenim: R"Z says that this is only if he slaughters on wood or stone, but if it is on land (earth), he need not put below. This requires investigation from Chulin 31a (a man shot an arrow at a flying bird, and this was a Kosher Shechitah. The Gemara asked that one must cover the blood also below. Why should the Gemara assume that it was over wood or stone, in order to ask?! - PF)