Hieroglyphics of Horapollo, tr. Alexander Turner Cory, [1840], at sacred-texts.com
If they would represent immoderate anger, so that he who is angry takes a fever thereby, they depict a LION BREAKING THE BONES OF ITS OWN WHELPS. And they portray the lion to signify anger, and the whelps having their bones broken, because the bones of the whelps when struck together emit sparks of fire.