Midrash for Chullin 70:43

מאי לאו הא דם שחיטה מכשיר

with regard to the blood of a slaughtered animal, and it would have been self-evident with regard to the blood from a wound! - It was necessary for him to state his view with regard to the blood from a wound, for I might have argued: What difference can there be [with regard to the blood] whether the animal was slain completely or partially?<span class="x" onmousemove="('comment',' The law should be the same with regard to the blood whether it comes from an animal completely slain, i.e., dead, or partially slain, i.e., wounded.');">¹⁵</span>

Sifrei Devarim