Emblematic of St. Luke. It is one of the four figures which made up Ezekiel's cherub (i. 10). The ox is the emblem of the priesthood, and has been awarded to St. Luke because he begins his gospel with the Jewish priest sacrificing in the Temple. (See Luke.)
The ox is also the emblem of St. Frideswide, St. Leonard, St. Sylvester, St. Medard, St. Julietta, and St. Blandina.
He has an ox on his tongue. (Latin, Bovem in lingua habere, to be bribed to silence The Greeks had the same expression. The Athenian coin was stamped with the figure of an ox. The French say, “Il a un os dans la bouche,” referring to a dog which is bribed by a bone.
The black ox hath trampled on you (The Antiquary). Misfortune has come to your house. You are henpecked. A black ox was sacrificed to Pluto, the infernal god, as a white one was to Jupiter.
The black ox never trod upon his foot (common proverb). He never knew sorrow. He is not married. (See above.
The dumb ox. St. Thomas Aquinas; so named by his fellow students at Cologne, on account of his dulness and taciturnity. (1224-1274.)
Albertus said, “We call him the dumb ox, but he will give one day such a bellow as shall be heard from one end of the world to the other.” (Alban Butler.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894