This is not said of debts of money only, but of all things in which any sins against us, and among these also of money, because that he sins against you, who does not return money due to you, when he has whence he can return it. Unless you forgive this sin you cannot say, “Forgive us our debts, as we forgive our debtors.”
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Serm. in Mont., ii, 8