From Haydock’s Commentary:
A received tradition of the Jews informs us, that this Lazarus was a beggar, then at Jerusalem, suffering in the most wretched condition of poverty, and infirmity: him our Saviour introduces, to manifest more plainly the truth of what he had been saying (St. Cyril, in Cat. Græc. patrum.) — By this, we are not to understand that all poverty is holy, and the possession of riches criminal; but, as luxury is the disgrace of riches, so holiness of life is the ornament of poverty. (St. Ambrose) — A man may be reserved and modest in the midst of riches and honours, as he may be proud and avaricious in the obscurity of a poor and wretched life. — Divers interpreters have looked upon this as a true history; but what is said of the rich man seeing Lazarus, of his tongue, of his finger, cannot be literal: souls having no such parts. (Witham) — In this parable, which St. Ambrose takes to be a real fact, we have the name of the poor mendicant; but our Lord suppresses the name of the rich man, to signify that his name is blotted out of the book of life: besides, the rich man tells Abraham, that he has five brothers, who were probably still living; wherefore, to save their honour, our Lord named not their reprobated brother.