Augustine of Hippo

Therefore "Jesus found a donkey and sat upon it." … The donkey's colt upon which no one had sat (for this fact is found in the other Evangelists) we understand as the people of the nations which had not received the Lord's law. However, the donkey (because both beasts were led to the Lord) is his community which came from the people of Israel, clearly not unbroken, but which recognized the Master's manger.