John Cassian

"If you offer rightly, but do not reason rightly, have you not sinned?" For those offerings of fasts, which we extort without thought by violently wrenching our stomachs and fancy that we rightly offer to the Lord, he who "loves mercy and judgment" denounces, saying: "I the Lord love judgment, but I hate robbery in a burnt offering." Similarly, those also who take the main part of their offerings, that is, their offices and actions, to benefit the flesh for their own use, but leave the remains as a tiny portion for the Lord, are also condemned as fraudulent workers by the Divine Word, saying: "Cursed is the one who does the work of the Lord fraudulently."