All four Gospels tell us about the donkey. Five days (by our reckoning) before the Passover, Jesus enters Jerusalem for the final time. "A great crowd" spread their coats on the road from Bethany to Jerusalem "at the Mount of Olives". A few cut down leafy branches and lay them before Jesus as he makes his way towards the Temple, shouting "Hosanna to the Son of David!"
The writers are clear about what is happening. This is the prophecy of Zechariah 9:9 coming true: "Rejoice greatly, O daughter Zion! Shout aloud, O daughter Jerusalem! Lo, your king comes to you; triumphant and victorious is he, humble and riding on a donkey, on a colt, the foal of a donkey." Matthew is so carried away by the way the prophecy is being fulfilled that he assumes there were two donkeys. But Zechariah's mention of the foal is to emphasize what sort of donkey it was - as Mark makes clear, an unridden one, for in the Old Testament, whatever is used in God's service should not have been previously used for secular purposes!
Why a donkey? There is a rather nice story that a Jewish rabbi two hundred years later predicted that if Jerusalem was worthy, the Messiah would come on the clouds of heaven, but if Jerusalem was unworthy, he would come riding on a donkey. But this anecdote does not explain Zechariah's prophecy. Riding a humble donkey suggests the kind of king who will come - one who will reign not by conquest and violence, but in peace.
What was certain, though, was that the crowds recognized Jesus as their king. Presumably their enthusiasm was not so great that the authorities would have felt the need to clamp down on it - for the Passover season was a time when passions were high and the Romans eager to avoid disturbances. (It is significant that the Roman procurator, Pilate, had come up to Jerusalem, and was not in his headquarters in Cæsarea at this season.) But it was enough for the Jewish establishment to be aware that their world was threatened with radical change.
Spreading clothes in the path of a great person as a sign of homage is one that has a long history. The "leafy branches" (John calls them palms, which makes sense!) may have recalled the dedication of the Temple under Simon Maccabæus two hundred years before (read all about it in 1 Macc 13, if your Bible includes it!). But the words the crowd shout give the clearest indication of what they thought.
"Hosanna" means "save" or "help" (to see the word in context, look at 2 Sam 14:4 or 2 Kings 6:26), and here the crowd's words recall Psalm 118:25 - a psalm which to the first Christians was full of references to Jesus. ("The stone which the builders rejected has become the chief cornerstone.") The son of David, the Messiah, will bring this help, which will reach not only to the ends of the earth, as Zechariah prophesied, but to the highest heaven as well. In this context, quoting the next verse of the psalm, "Blessed is the one who comes in the name of the LORD", confirms that the crowd, in the eyes of all four evangelists, were welcoming Jesus not only as king, but as Messiah.
In the first three Gospels, Jesus' entry into Jerusalem is followed by a visit to the Temple, where he overturns the tables of the money-changers and the seats of the pigeon-traders. The LORD, as Malachi predicted, has come, suddenly. The point is not that the traders were swindlers, nor is it that they were defiling holy ground (for how else could people obtain animals to sacrifice or change their heathen money (with Cæsar's head on it) into currency that complied with the Bible's ban on images?) The point is that the rôle of the Temple is drawing to an end. The One who comes in the name of the LORD will put an end to the time when people need to burn cows or slit the throats of sheep to win God's favour.
For the donkey carried on its back the one who had come to put an end to these crude offerings. Here was the Passover lamb who would take away the world's sin and misery, and would save us all, once and for all time. Here was the one whose gift to us was God's own life, not riding on a glorious and majestic cloud, but riding on a donkey.
HD