Chabad.org — English translation + Rashi
Torah Temimah points to Kerisos 4b.
E-Daf.com — Kerisos 4b
HebrewBooks / Shas PDF
English: It was taught: “All fat and all blood you shall not eat” — blood is compared to fat: just as fat is distinctive in that its fat is separate from its flesh and they do not combine…
Hekesh of blood to chelev — blood and chelev share liability structure; they do not combine with ordinary meat for the shiur.
Blood and chelev share liability structure; they do not combine with ordinary meat for the shiur. The hekesh established by the joint prohibition teaches that blood, like chelev, is treated as a distinct substance whose minimum quantity for liability is calculated independently of ordinary flesh. The result is a parallel formal structure for the two prohibitions.