NUM13 It is a positive commandment that a sinner should turn back from his sin, and should confess his mistakes before the blessed God as Scripture says, When a man or a woman commit any sin… then they shall confess their sin [this and preceding verse]. This means an avowal in words before the blessed God. He is to say, from the depths of his heart, "I beseech You Hashem: I have sinned, done wrong, and acted criminally before You. This-and-this I did (and he has to describe the scene in detail); and here I have regretted my deed and become ashamed of it. Never will I go back and do this thing again." The main element [of repentance] is remorse in the heart, in truth, over the past; and one must take it upon himself not to do such a thing ever again. This [confession] is the essential part of repentance; but the more one confesses, the more praiseworthy he is. Even death and the confession on Yom Kippur, however, bring no atonement [and forgiveness] unless they are with repentance.