Why is this recorded here, this little event? Well is the Lord's way of preparing the disciples, at least two of them, for the week that lies ahead. He is in control of all that is now about to happen. In due course he will be arrested in apparent weakness, crucified, slain; he knows what he is doing. His divine omniscience is arranging all things; there is no mistake in anything that is about to happen, even though it will shake the faith of the disciples. He is heading into this voluntarily, intentionally; he is God and he is entirely in charge. So this seemingly small practical arrangement is faithfully recorded because it was there to comfort and to strengthen.
But there is a further reason. Matthew writing for Jewish readers tells us, ‘All this was done, that it might be fulfilled which was spoken by the prophet, saying, 5 Tell ye the daughter of Sion, Behold, thy King cometh unto thee, meek, and sitting upon an ass, and a colt the foal of an ass’ (Matthew 21:4-5). This was a fulfilment of Zechariah 9:9, in which the prophet describes the coming of Israel’s long-awaited King. He will be so different to the kings of this world, who seek acclaim from men and who take offence if their status is not recognized. Christ will come divested of all earthly trappings, and will enter Jerusalem to take his place as her rightful king. But he will come as an accessible King, who is ready to identify with the lowly, whom no one who is ready to confess their sins and repent of them should be afraid to approach. He will receive them. How many very specific prophecies about Christ were fulfilled during his incarnation. Who else in history has been the subject of so many detailed predictions, given hundreds of years before he was born. These are not vague prophecies what could be interpreted in any number of ways. They are very specific and very clear, and only one man in all of history has fulfilled them.