Kabbalah su Abacuc 3:8

It is not the custom of the King and the Matron to ride a donkey (Heb. chamor), [Meaning, the literal understanding of the Torah is referred to as Chomer, which is similar to Chamor, and is comprised of wheat and the tree of knowledge of good and evil]. Instead they ride on horses. ['Horses' here corresponds to the secrets and mysteries of the Torah]. This is the meaning of, "you ride upon your horses, your chariots of salvation" (Habakuk 3:8). For Malchut is not treated lightly so as to have the Matron ride on a donkey, and even more so the King, for it is no place for commoners and servants, [The angel Metatron is called a commoner and servant] whose way is to ride a donkey. This is why it says of Messiah, "humble (Heb. ani), and riding upon an donkey" (Zechariah 9:9). Ani stands for the Mishnah orders of Eruvin, Nidah and Yevamot, [Ani also means "poor"] and the rest of the Mishnah in total. [ As long as a person does not know the mysteries of the Torah, but only knows the revealed Torah, one is "poor" in knowledge and it is like he is "riding on a donkey", which is the aspect of the Tree of Knowledge of Good and Evil. However, Hashem] is not considered a King until He rides on His horse, which is the Congregation of Yisrael [ This is Malchut/Kingship. See Song of Songs 1:9 "I have likened you, my darling, To a mare in Pharaoh’s chariots"].