A married man committed adultery, how is he to repent?

Abu Huraira (may God be pleased with him) said: "I heard the Prophet (peace and blessings be upon him) say: "All members of my community are pardoned except for those who divulge their sins.” Among those who announce their sins is someone who commits a crime by night; God conceals it, yet when morning comes he says, "O, so-and-so! Yesterday I did such-and-such." He spent the night with his sins covered by his Lord, and when he wakes up he exposes what God has concealed" [Bukhari and Muslim].

A person who commits a sin must refrain from divulging it when God the Almighty has concealed it from others; one of the attributes of God the Almighty is concealing human faults and failings. A person who announces his sins when God the Almighty has concealed them attaches little importance to His protection and is ungrateful to His grace and mercy. Repentance is by:
- Desisting from one's sin.
- Regretting having done it.
- Resolving never to commit it again.
- Asking for God’s forgiveness in abundance.

God the Almighty commands a person who has committed a sin for which there is a prescribed legal punishment to conceal it rather than to strive to have the punishment administered on him. The ruler is the one to exact punishments as it is one of his duties.

It was reported that a man, Ma'iz Ibn Malik, fornicated with a slave girl who was not permissible for him. Huzal ordered him to go to the Prophet (peace and blessings be upon him) before whom Ma'iz testified against himself four times. After ordering that he be stoned to death, the Prophet (peace and blessings be upon him) turned to Huzal and said: "It would have been better if you had covered him with your cloak" [Abu Dawud and Al-Nisai].