What does the Pasuk mean when it writes "Damo b'Nafsho Hu"?
Rashi#1: It means that the existence of the Soul (life) depends upon the blood. 1
Rashi #2 (in Pesachim 68a): It means to preclude Dam ha'Tamzris (the blood that drips out before or after the Dan ha'Nefesh and does not flow) from Kareis. 2
Ramban: "Nafsho" here means the body, 3 and what the Pasuk is saying is that 'the Soul of all flesh lies in the blood which is in the body'.
Seforno: It means that the Soul of all flesh is synonymous which the Soul, inasmuch as the vaporized part of the blood 4 supports the life-force that is contained in the Soul.
Refer to 17:12:1:1*.
Though it is still subject to a La'av.
As in Shemos 1:5 and in Bamidbar 6:6 (Ramban).
Which in turn, is the food of the Sheidim.
Why does the Torah write here "Damo be'Nafsho" and in Pasuk 11 "Ki Nefesh ha'Basar be'Dam hu"?
Refer to 17:14:2:1 and note.
Why does the Torah insert the (otherwise superfluous) words "Va'omar li'Venei Yisrael"?
Refer to 17:13:3.1:3.
Why does the Torah equate the blood and the Nefesh three times - once on Pasuk 11, and twice in the current Pasuk?
Ramban: First it states that the Soul lies in the blood, then, that the blood lies in the Soul, and finally that two merge into one, 1 so that there is no such thing as blood without Nefesh or Nefesh without blood.
Which are one and the same - like wine that is diluted with water (Ramban).
Why does the Torah repeat the Chiyuv Kareis for consuming blood three times (One above (7:27), and twice in the current Parshah, in Pesukim 11, 14)?
Kerisus, 4b: One is for Dam Kodshim, one for Dam Chulin 1 , and one for Dam Kisuy.
Ramban: I.e. Dam ha'Nefesh of Kodshim, and Dam Shechitah of Chulin. See R. Chavel's footnotes.
Why does the Torah write "Kol Ochlav" (plural) "Yikareis" (singular)?
Oznayim la'Torah: "Yikareis" refers to "Kol", and the Torah writes "Ochlav" with reference to thetwo reasons why a person drinks blood: 1. in order to communicate with the Sheidim in order to discover the future; 2. for health reasons. And since one may think that it is only the former - which is a form of Avodah Zarah - that is subject to Kareis, the Torah inserts the word "Kol" to teach us that the Chiyuv Karis applies irrespective of the reason.
Why does the Torah juxtapose the Isur of Neveilah and T'reifah to that of Dam?
Oznayim la'Torah: Because, in Pasuk 13, it discussed hunting Chayos and Ofos, which often entails using a bow and arrows, which in turn, sometimes resuls in rendering the Chayah or the Of a Neveilah or a T'reifah. The Torah therefore issues a warning against eating it.
Why does it say "v'Omar li'Vnei Yisrael"?
Moshav Zekenim: This is right after "Damo b'Nafsho Hu", to teach that if the Shochet will not cover it, others are obligated to cover it. However, if he intends to cover it, and someone else covered it, he must pay 10 gold coins for 'stealing' his Mitzvah. (Chulin 87a)