Midrash su Salmi 80:8

Binding his foal unto the vine, and his ass’s colt unto the choice vine (Gen. 49:11). Vine refers to Israel, as is said: Thou didst pluck up a vine out of Egypt (Ps. 80:9). Binding his foal (‘iroh) alludes to the Holy City (‘ir ha-kodesh). Unto the choice vine refers to Israel, as is said: Yes, I have planted thee a choice vine (Jer. 2:11). And his ass’s colt implies that they will build a gate for the temple.²²A play on words: benei atono (asses colt) with yivnu (will build) and atun (the fireplace of the Temple).