This is probably just Set sexually assaulting Horus again, and Horus catching his semen and wiping it on some lettuce, which we all know is Set's favourite.* Things should calm down when they've settled it with a boat race, like they did last time.
Perfectly reasonable explanation. Not like these newer religions. Some of them claim to eat the flesh and drink the blood of their God, then sing songs about it. Or they're huge fans of cutting bits off boys' penises. Cannibalistic creeps and weirdos. Keep fighting with each other about their favourite demi-god. Why anyone takes them seriously is beyond me.