leviticus 17:10 And whatsoever man there be of the house of Israel, or of the strangers that sojourn among you, that eateth any manner of blood; I will even set my face against that soul that eateth blood, and will cut him off from among his people. - Free Bible Online

      10. I will even set my face against that soul that eateth blood, and will cut him off from among his people--The face of God is often used in Scripture to denote His anger (Ps 34:16; Re 6:16; Eze 38:18). The manner in which God's face would be set against such an offender was, that if the crime were public and known, he was condemned to death; if it were secret, vengeance would overtake him. (See on Ge 9:4). But the practice against which the law is here pointed was an idolatrous rite. The Zabians, or worshippers of the heavenly host, were accustomed, in sacrificing animals, to pour out the blood and eat a part of the flesh at the place where the blood was poured out (and sometimes the blood itself) believing that by means of it, friendship, brotherhood, and familiarity were contracted between the worshippers and the deities. They, moreover, supposed that the blood was very beneficial in obtaining for them a vision of the demon during their sleep, and a revelation of future events. The prohibition against eating blood, viewed in the light of this historic commentary and unconnected with the peculiar terms in which it is expressed, seems to have been levelled against idolatrous practices, as is still further evident from Eze 33:25, 26; 1Co 10:20, 21.

JFB.