Histories 2.39

1 After leading the marked beast to the altar where they will sacrifice it, they kindle a fire; then they pour wine on the altar over the victim and call upon the god; then they cut its throat, and having done so sever the head from the body.

2 They flay the carcass of the victim, then invoke many curses on its head, which they carry away. Where there is a market, and Greek traders in it, the head is taken to the market and sold; where there are no Greeks, it is thrown into the river.

3 The imprecation which they utter over the heads is that whatever ill threatens those who sacrifice, or the whole of Egypt, fall upon that head.

4 In respect of the heads of sacrificed beasts and the libation of wine, the practice of all Egyptians is the same in all sacrifices; and from this ordinance no Egyptian will taste of the head of anything that had life.