Ambrose of Milan — as excerpted in the Catena Aurea on Luke 14:15-24

“He invites the poor, the weak, and the blind, to shew that weakness of body shuts out no one from the kingdom of heaven, and that he is guilty of fewer sins who lacks the incitement to sin; or that the infirmities of sin are forgiven through the mercy of God. Therefore he sends to the streets, that from the broader ways they may come to the narrow way. Because then the proud refuse to come, the poor (Greg. Hom. 36.) are chosen, since they are called weak and poor who are weak in their own judgment of themselves, for there are poor, and yet as it were strong, who though lying in poverty are proud; the blind are they who have no brightness of understanding; the lame are they who have walked not uprightly in their works. But since the faults of these are expressed in the weakness of their members, as those were sinners who when bidden refused to come, so also are these who are invited and come; but the proud sinners are rejected, the humble are chosen. God then chooses those whom the world despises, because for the most part the very act of contempt recals a man to himself. And men so much the sooner hear the voice of God, as they have nothing in this world to take pleasure in. When then the Lord calls certain from the streets and lanes to supper, He denotes that people who had learnt to observe in the city the constant practice of the law. But the multitude who believed of the people of Israel did not fill the places of the upper feast room. Hence it follows, And the servant said, Lord, it is done as thou hast commanded, and yet there is room. For already had great numbers of the Jews entered, but yet there was room in the kingdom for the abundance of the Gentiles to be received. Therefore it is added, And the Lord said unto the servant, Go out into the highways and hedges, and compel them to come in, that my house may be filled. When He commanded His guests to be collected from the wayside and the hedges, He sought for a rural people, that is, the Gentiles.”