—yet he is himself among the most relentless backbiters—may Allah grant us safety—or he groans about the spread of lying and the loss of trustworthiness among people while he is one of the biggest liars and the most negligent in keeping trusts!
In any case, a person must abandon the sin from which he claims to have repented; if he does not, his repentance is rejected and will be of no benefit to him before Allah. Desisting from sin may concern a matter that is purely Allah’s right. In that case it is enough to repent privately between you and your Lord, and it is neither proper—indeed, we may say it is forbidden—to tell others about the unlawful deed you committed or the duty you failed to perform. This affair is between you and Allah. If Allah has blessed you with concealment and has hidden your lapse from His servants, then once you have repented to Him do not disclose it to anyone.
The Prophet (peace and blessings be upon him) said, “Every member of my community will be pardoned except those who sin openly.” Among the forms of openly sinning, as he explained, is “for a man to commit a deed in the night that Allah has veiled, then in the morning he says, ‘O so-and-so, I did such-and-such last night…’” and the like.
Some scholars have added that if the sin entails a prescribed punishment, there is no harm in the person going to the authority charged with applying the penalties—such as the ruler—and confessing, seeking purification through the punishment. Even then, however, it is still better for him to keep the matter concealed.