“gross misinterpretation...”
Absolutely not. The Douay Rehiems bible is the closest translation to the original Latin and Greek that is out there. Later “bibles” contain modern error. The Douay Rheims is base 100% on the original Latin and Greek vulgate translated by St. Jerome himself.
That's a mighty broad brush yer swingin' at an ill defined target.
Could ye be a wee bit more specific?
Fail.....
Acts 2:38 http://biblehub.com/text/acts/2-38.htm
Metanoesate = repent
http://biblesuite.com/greek/3340.htm
metanoeo: to change one's mind or purpose
Transliteration: metanoeó
Phonetic Spelling: (met-an-o-eh'-o)
Short Definition: I repent, change my mind
Definition: I repent, change my mind, change the inner man (particularly with reference to acceptance of the will of God), repent.
3340 metanoéō (from 3326 /metá, "changed after being with" and 3539 /noiéō, "think") properly, "think differently after," "after a change of mind"; to repent (literally, "think differently afterwards").
Word Origin - from meta and noeó
Definition - to change one's mind or purpose
Then please show the Greek source that used the word that can be translated do penance.