As early as Genesis 9:4, the Old Testament teaches that there is life in blood and that life belongs to the Lord. It is forbidden to eat the blood of the sacrificial animals because it is used for atonement and belongs to the Lord. The instructions regarding the blood prohibition is gradually developed as the book of Leviticus unfolds. It is introduced in Leviticus 3:17. More detail is provided in Leviticus 7:23b-Leviticus 7:24–27. Lastly, in Leviticus 17:10–11, the rationale for the injunction is explicitly stated.
26 Moreover, you shall eat no blood whatever, whether of fowl or of animal, in any of your dwelling places.