Origen
Catena Aurea · Lukasevangelium 19
And when he had thus spoken, he went before, ascending up to Jerusalem. And it came to pass, when he was come nigh to Bethphage and Bethany, at the mount called the mount of Olives, he sent two of his disciples, Saying, Go ye into the village over against you; in the which at your entering ye shall find a colt tied, whereon yet never man sat: loose him, and bring him hither. And if any man ask you, Why do ye loose him? thus shall ye say unto him, Because the Lord hath need of him. And they that were sent went their way, and found even as he had said unto them. And as they were loosing the colt, the owners thereof said unto them, Why loose ye the colt? And they said, The Lord hath need of him. And they brought him to Jesus: and they cast their garments upon the colt, and they set Jesus thereon. And as he went, they spread their clothes in the way.
There were then many masters of this colt, before that the Saviour had need of him. But as soon as He began to be the master, there ceased to be any other. For no one can serve God and mammon. (Matt. 6:24.) When we are the servants of wickedness we are subject to many vices and passions, but the Lord has need of the colt, because He would have us loosed from the chain of our sins.