Histories 2.132

1 As for the cow, it is covered with a purple robe, only the head and neck exposed, encrusted with a very thick layer of gold. Between the horns is the golden figure of the sun's orb.

2 It does not stand, but kneels; it is as big as a live cow of great size. This image is carried out of the chamber once every year, whenever the Egyptians mourn the god whose name I omit in speaking of these matters:

3 then the cow is brought out into the light; for they say that before she died she asked her father, Mycerinus, that she see the sun once a year.