They committed adultery and claimed to have repented but continued to commit sins and be alone together. She became pregnant and he got permission to marry her from her father, who was unaware. They performed the marriage and some people who were aware of their situation told them that their marriage is invalid because the repentance was incomplete, the woman was in her 'Iddah (waiting period), and the father was not aware that she was pregnant when he gave his permission. Afterwards, they shopped around for some Sufi fatwas that would validate their actions and presented them as evidence for what they claim: that the child belongs to and can be named after him and that it is permissible to marry her during her 'Iddah to hide the sin that they committed. They were told that hiding the sin means not revealing or disclosing it and that it does not mean following desires and deceit. Today, they live together in a rental contract after celebrating a baby shower. We want to know what is obligatory upon them so that we can advise them. Is this marriage valid and does this deceit prevent marriage in the future (like in case the child would murder the father to receive his inheritance, would it be prevented from him)? Please do not respond with similar questions as we have read them and did not find in them what was sufficient for this situation. May Allah reward you with good.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.

The view that we adopt here at Islamweb is that the marriage of the man and woman who committed Zina (fornication or adultery) is not valid except after sincere repentance and making sure that the woman is not pregnant and that the child born out of wedlock is not traced to the fornicator under any circumstances. 

However, some scholars are of the view that it is permissible for the fornicator to conduct a marriage contract with the woman whom he committed Zina with during her pregnancy and that the child is traced back to him as long as the woman is not someone else's wife and no one disputed with him regarding the tracing back of the child.

Ibn Qudaamah said:

“The illegitimate child is not traced back to the fornicator (or adulterer) according to the view of the majority of the scholars. Al-Hasan and Ibn Seereen said, 'The child is traced back to the fornicator if the Hadd (i.e. the corporal punishment determined by Islamic Law) of Zina is applied on him, and he inherits from him.' Ibraaheem said, 'He is traced back to him if he is lashed according to the Hadd that applies to him or if he had married the woman whom he had illegal sexual intercourse with.' Is-haaq said, 'The child is traced back to him.' ‘Urwah and Sulaymaan ibn Yassaar said the same thing. Ali ibn 'Aasim narrated from Abu Haneefah that he said, 'I do not see any harm if a man marries the woman with whom he impregnated from Zina during her pregnancy and that he conceals her sin and the child is traced back to him.'”

We recommend that the man and the woman (the fornicators) sincerely repent to Allaah and seek forgiveness and perform righteous deeds as much as possible. They should conceal their sin and not inform anyone about it because talking about the sin (informing others about it) is another sin that adds to the previous sin.

In case they sought a fatwa from someone who is trustworthy in his knowledge and piety, then it is permissible for them to act upon the fatwa that he issued to them, especially if acting upon that fatwa brings about a benefit or wards off a harm that could not be avoided otherwise.

Allaah knows best.