9 And in saying, “A ruler shall not depart from Judah, nor a leader from his thighs, until he come for whom it is reserved; and he shall be the expectation of the nations,” he referred the fulfilment (of that prophecy) to Christ. For He is our expectation. For we expect Him, (and) by faith we behold Him as He comes from heaven with power.
10. “Binding his ass to a vine:”that means that He unites His people of the circumcision with His own calling (vocation). For He was the vine. “And his ass's colt to the vine-tendril:”that denotes the people of the Gentiles, as He calls the circumcision and the uncircumcision unto one faith.
11. “He shall wash his garment in wine,” that is, according to that voice of His Father which came down by the Holy Ghost at the Jordan. “And his clothes in the blood of the grape.” In the blood of what grape, then, but just His own flesh, which hung upon the tree like a cluster of grapes?— from whose side also flowed two streams, of blood and water, in which the nations are washed and purified, which (nations) He may be supposed to have as a robe about Him.
12. “His eyes gladsome with wine.” And what are the eyes of Christ but the blessed prophets, who foresaw in the Spirit, and announced beforehand, the sufferings that were to befall Him, and rejoiced in seeing Him in power with spiritual eyes, being furnished (for their vocation) by the word Himself and His grace?
Source: The Antichrist (New Advent)