Mongoose & Cobra question.?

Okay so recently I was watching some YouTube videos and I came across a Mongoose fighting, killing and eating a Cobra, and a thought crossed my mind. Now I know the Cobras venom only lies in his bite but wouldnt the poison some how enter into the Mongooses (or any other animal that eats a poisonous animal for that matter) body and eventually kill/poison the Mongoose? Im just curious as to how that exactly works. Or what about an animal that eats a poisonous animal and the poison is on their flesh? How do they not die or get some kind of effects from the poisons on or in the other animals body? Lol this curious mind would appreciate any and all feed back. (Sorry ahead of time if this seems like a dumb question to some. But as they say: "There are no dumb questions" lol)