Augustine was preaching on the parable of the great supper (Lk 14:16-24) from which three of those invited give excuses why they can’t come, whose places are taken by the poor and the feeble, the blind and the lame:

Let us set aside all lame and poor excuses, and let us come to the dinner by which we will be filled inwardly.... Let us come and be filled. ... Let beggars come because he invites them who, though he was rich, became poor for our sake so that we beggars might be enriched by his poverty (2 Cor 8:9). Let the weak come because it is not the healthy but the ill who need the physician (Mt 9:12). Let the lame come who say to him: “Settle my steps in your paths” (Ps 16:5). Let the blind come who say: “Enlighten my eyes so that I shall never fall asleep in death.” (Ps 12:4) (Sermon 112, 8; PL 38, 647)