“דַּבֵּר אֶל־בְּנֵייִשְׂרָאֵל לֵאמֹר כָּל־חֵלֶב שׁוֹר וְכֶשֶׂב וְעֵז לֹא תֹאכֵלוּ” (ויקרא ז׳:כ״ג).
In the middle of discussing the sacrifices, the Torah takes a slight detour todiscuss the forbidden parts of animals—the fat and the blood. The fat and theblood are the parts of the korban that are sacrificed on the altar. The fatsare burned at the end of the day and the blood is sprinkled or poured on thealtar. Because these two parts of the sacrifices are exclusively for ה׳, they are forbidden for humanconsumption. The Tur, Yoreh Deah 64 explains that this verse, “דַּבֵּר אֶל־בְּנֵי יִשְׂרָאֵל לֵאמֹר כָּל־חֵלֶב שׁוֹר וְכֶשֶׂב וְעֵז לֹא תֹאכֵלוּ” (ויקרא ז׳:כ״ג),comes to teach that the fat is only prohibited on these kosher animals. Fat ofa non-kosher animal is simply prohibited as eating a non-kosher animal.

Another reason that blood isprohibited is presented later in Deuteronomy:
“רַק חֲזַק לְבִלְתִּי אֲכֹל הַדָּם כִּי הַדָּם הוּא הַנָּפֶשׁ וְלֹא־תֹאכַל הַנֶּפֶשׁ עִם־הַבָּשָׂר” (דברים י״ב:כ״ה).
Meam Loez also points to a verse later in Leviticus:
“לֹא תֹאכְלוּ עַל־הַדָּם לֹא תְנַחֲשׁוּ וְלֹא תְעוֹנֵנוּ” (ויקרא י״ט:כ״ו).
The prohibition against divination shares the verse with the prohibitionagainst consuming blood to link the two. Blood was an important part of paganrituals. The prohibition against blood is another key demarcation between theholy sacrificial service and the idol worship of the gentiles. In modern times,divination from blood has extended to Elizabeth Holmes and her Therenousproject which claimed to be able to divine all diseases from the blood alone. Withthese two prohibitions, ה׳is further protecting the special sacred space of the korbanot by restrictingthe rituals from becoming a pagan free-for-all.