Plutarch, De Iside et Osiride
Goodwin, Ed.

And because the Egyptians are of opinion that Typhon was born of a red complexion, they are therefore used to devote to him such of the neat kind as they find to be of a red color; and their observation herein is so very nice and strict that, if they perceive the beast to have but one hair about it that is either black or white, they account it unfit for sacrifice. For they hold that what is fit to be made a sacrifice must not be of a thing agreeable to the Gods, but contrariwise, such things as contain the souls of ungodly and wicked men transformed into their shapes. Wherefore in the more ancient times they were [p. 92] wont, after they had pronounced a solemn curse upon the head of the sacrifice, and had cut it off, to fling it into the river Nile; but now they distribute it among strangers. Those also among the priests that were termed Sphragistae or Sealers were wont to seal the beast that was to be offered; and the engraving of their seal was (as Castor tells us) a man upon his knees with his hands tied behind him, and a knife set under his throat. They believe, moreover, that the ass suffers for being like him (as hath been already spoken of), as much for the stupidity and sensualness of his disposition as for the redness of his color. Wherefore, because of all the Persian monarchs they had the greatest aversion for Ochus, as looking upon him as a villanous and abominable person, they gave him the nickname of the ass; upon which he replied: But this ass shall dine upon your ox. And so he slaughtered the Apis, as Dinon relates to us in his history. As for those that tell us that Typhon was seven days flying from the battle upon the back of an ass, and having narrowly escaped with his life, afterwards begat two sons called Hierosolymus and Judaeus, they are manifestly attempting, as is shown by the very matter, to wrest into this fable the relations of the Jews.