משנה אויף ויקרא 17:11

Rabbi Ishmael says: [the law relating to] blood is lenient at the beginning [before it is offered] and stringent at the end; [the law relating to] libations is stringent at the beginning and lenient at the end. Blood at the beginning is not subject to the law of sacrilege, but is subject to it after it has flowed away to the Wadi Kidron. Libations at the beginning are subject to the law of sacrilege, but are exempted from it after they flowed down into the shitin.

The sacrifices of non-Jews: one is not liable on their account for piggul, remnant, or defilement, and if [a priest] slaughters them outside [the Temple], he is not liable, the words of Rabbi Meir. But Rabbi Yose declares him liable. The things for which one is not liable on account of piggul, one is liable on account of remnant and defilement except blood. Rabbi Shimon declares one liable for anything which is normally eaten, but for wood, frankincense and incense, one is not liable for [transgressions involving] defilement.

If one ate blood of a slaughtered beast, a wild animal or a bird, either clean or unclean, or blood of an animal stabbed in his throat or neck, or of the blood of an animal slaughtered by having his throat ripped, or of the blood of the arteries whereby life-force escapes, he is liable. But [if he ate] the blood of the spleen or of the heart, or blood found in eggs, or blood of fish, or of locusts, or secondary blood, he is not liable. Rabbi Judah says: he is liable for secondary blood.