Today, Christians celebrate Palm Sunday -- the day when Jesus rode into Jerusalem to great "Hosanna!" acclaim. But just exactly how did he do it? The stories disagree in a puzzling way... unless you know something about the conventions of biblical Hebrew and that the New Testament writers (Matthew, especially) often looked to the Old Testament, for ways to understand Jesus.
Mark and Luke agree that Jesus rode in a donkey, and that's the story that's told in thousands of churches today. Matthew, on the other hand, has Jesus riding two beasts at the same time. An odd, albeit remarkable(!) feat to include. Unlike the other two, Matthew explains that Jesus did so to fulfill the scriptures (Hebrew Bible), and he partly quotes the reference in Zechariah, writing, "Tell the daughter of Zion, 'Look your king is coming to you, humble and mounted on a donkey, on a colt, the foal of a donkey.'" That quote usually makes it into contemporary Palm Sunday retellings because of how it underscores the unusual nature of Jesus' kingship -- humble, in this case. But the bit about simultaneously riding both a donkey and a colt gets glossed thanks to Mark and Luke.
Zechariah's text appears as poetry, and the primary characteristic of biblical Hebrew poetry is parallelism. In its purest form, one line is followed by another that repeats its sense. Here's a great example from Proverbs 4:6 (about the importance of wisdom): "Do not forsake her, and she will keep you/ love her, and she will guard you." Get it? "Do not forsake her" is parallel to "love her," "she will keep you" is parallel to "she will guard you." Sometimes the parallelism is not so tidy, though, but rather integrated into a sort of stepped structure that builds with repetition. That's true in Zechariah 9:9 which ends, "riding on an ass [hold the jokes here];... on a donkey, the son of a she-beast." Now add this additional bit of info about Hebrew convention: one single letter serves as every conjuction (our "and," "but," or "or"), and sometimes it shouldn't really be translated at all.
That little letter appears right before "on a donkey," so together with what you now know about Hebrew poetry, you can see that Matthew went literal with his quote. He read Zechariah without poetic parallelism (but rather as a straightforward narrative) and translated the shadow conjunction literally, too. The result: Jesus enters Jerusalem straddling two animals. Spoiler alert: this will not be Jesus' final miracle. The "good news" gospel writers agree on that.