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)