How can I ensure Allah accepts my repentance after committing lewd acts with a non-Muslim woman, who then embraced Islam, and I married her without witnesses? What is the ruling on the marriage contract and the child resulting from it? Is naming the child "Muhammad" considered a desecration of the name in this case? And how can I impose the hadd punishment upon myself to purify myself from sins?

The marriage mentioned is void for several reasons:

1. Marrying a non-chaste woman of the People of the Book: The Sharia stipulated chastity (purity) for a woman of the People of the Book to be married, and the questioner mentioned her committing immorality. 2. The marriage was conducted without a guardian (wali) or witnesses: The guardian and witnesses are conditions for the validity of the marriage contract (nikah).

As for the child, he is the son of the questioner, and his lineage is attributed to him if the waiting period ('iddah) from the mother's previous marriage had ended. The invalidity of the marriage does not affect the establishment of paternity. There is no objection to naming him Muhammad.

Regarding the implementation of the hudud punishment, it is preferable to conceal oneself and suffice with sincere and true repentance, as the Prophet, peace and blessings be upon him, said: "Avoid these abominations that Allah Almighty has forbidden. Whoever commits any of them should conceal himself with Allah's concealment and repent to Allah."