Hieroglyphics of Horapollo, tr. Alexander Turner Cory, [1840], at sacred-texts.com
When they would symbolise a man whose temperance is easily changed and inconstant, they depict a BULL WITH HIS RIGHT KNEE BOUND ROUND; for if you bind him by a fetter on his right knee, you will find him follow 1. And the bull is always assumed as a symbol of temperance, because it never approaches the cow after conception.
134:1 Treb. from τοῦτον, sic enim non coit, "for thus he holds no intercourse."