The Old Testament Prophecy of Jesus' triumphal entry into Jerusalem is found in Zechariah 9:9. The fulfillment, his welcome by "the whole crowd of disciples," is found in Luke 19:29-40. https://www.howthebiblefitstogether.org/files/Luke-19.29-40a-Triumphal-Entry.pdf

Zechariah 9:9b is a chiasm with "a donkey" being used in both the first and last phrase. The center which is being emphasized is the colt, which Jesus road. https://www.howthebiblefitstogether.org/files/Zech-9.9a-Chiasm.pdf