Deuteronomy 15:23

רק את דמו לא תאכל ONLY THOU SHALT NOT EAT THE BLOOD THEREOF — This prohibition appears to be redundant, since the blood of no animal may be eaten, but it is mentioned, in order that you should not think: since it (the blemished firstborn animal) is something that in every respect is permitted originally it belonged to a forbidden class of animals — for, you see, it was holy and yet it may be slaughtered outside the Temple, and may be eaten without redemption — and consequently you might think that its blood is also permitted, Scripture therefore states, “However thou shalt not eat its blood”.

רַ֥ק אֶת־דָּמ֖וֹ לֹ֣א תֹאכֵ֑ל עַל־הָאָ֥רֶץ תִּשְׁפְּכֶ֖נּוּ כַּמָּֽיִם׃ {פ}

Only thou shalt not eat its blood; thou shalt pour it upon the ground like water.