He committed zina with a woman then incited her to get divorced from her husband, then he married her after they had both repented from this sin of zina, then they regretted what they had done
Question

                One of my friend had committed zina with a married woman several times and then he promised her that if she gets divorced from her husband he will marry her. The woman took the divorce and got married to my friend, both of them had repented to Allah for the Zina committed and they have two children also. Recently he read your question and answer number 201510 where it is mentioned that If a person turns a woman against her husband and spoils her for him so that she leaves him, then he marries her, his marriage is not valid and they must be separated, according to the view favoured by Shaykh al-Islam Ibn Taymiyyah (may Allah have mercy on him). This is also the view of the Maalikis. Now both of them are crying and repenting to Allah for their gravest sin. Now what should they do? If they go separate with each other, what would happen to their children. Please guide him for the sake of Allah. He is the follower of Hanafi thoughts.
Praise be to Allah.
    Firstly: 

    What this man did of committing 
    zina with a married woman, then inciting her to leave her husband and ask 
    him for a divorce is a great crime and a major sin, and it is a blatant 
    immoral act which is indicative of the doer’s lack of religious commitment 
    and lack of respect for the limits set by Allah, may He be glorified and 
    exalted. That is because zina (adultery) is an abhorrent crime according to 
    all divinely-revealed laws, as is well known, and turning a woman against 
    her husband is a grave sin, in addition to the sin of zina. A stern warning 
    has been issued concerning it, as in the hadeeth of the Prophet (blessings 
    and peace of Allah be upon him): “He is not one of us who turns a woman 
    against her husband.” Narrated by Abu Dawood (2175); classed as saheeh by 
    al-Albaani in Saheeh Abi Dawood. Abu Dawood (5170) also narrated that 
    Abu Hurayrah said: The Messenger of Allah (blessings and peace of Allah be 
    upon him) said: “Whoever turns a man’s wife or slave against him is not one 
    of us.” Classed as saheeh by al-Albaani in Saheeh Abi Dawood.

    Shaykh ‘Abd al-‘Azeem Abaadi 
    (may Allah have mercy on him) said: “Whoever turns a woman against her 
    husband” by mentioning the husband's bad qualities in the presence of his 
    wife, or by mentioning the good qualities of a “stranger” (one who is a non-mahram 
    to her) in her presence.

    ‘Awn al-Ma‘bood, 
    6/159 

    He also said: “Whoever turns a 
    man’s wife against him” means by deceiving her or turning her against her 
    husband, and encouraging her to get divorced so that he can marry her, or so 
    that he can arrange her marriage to someone else, and so on.

    ‘Awn al-Ma‘bood, 
    14/52 

    Secondly: 

    What this woman did of 
    committing zina with that man is a grave sin and a betrayal of her husband 
    and a denial of his marital rights. The punishment of this crime for one who 
    is married – whether a man or a woman – is stoning to death, as is well 
    known from the mutawaatir Sunnah. 

    Moreover, her asking her husband 
    for divorce when there is no good reason for that is haraam, and a stern 
    warning has been issued concerning that in the words of the Prophet 
    (blessings and peace of Allah be upon him): “Any woman who asks her husband 
    for a divorce when there is no good reason, the fragrance of Paradise will 
    be denied to her.”

    Narrated by at-Tirmidhi, 1187; 
    classed as saheeh by al-Albaani in Saheeh Abi Dawood 

    Thirdly: 

    Some of the scholars are of the 
    view that if a man turns a woman against her husband, it is not permissible 
    for him to marry her; rather she becomes forbidden to him for eternity. This 
    is the view of the Maalikis. 

    However the majority of scholars 
    are of the view that such a marriage is valid, even though they have sinned 
    by doing what they did. This has been discussed previously in fatwa no.
    84849 

    What appears to be the case in 
    this situation is that so long as this man regrets what he did, and the 
    woman regrets it likewise, and they have repented to Allah, may He be 
    glorified, from the sin of zina before marriage, then they both have to 
    repent again, sincerely and truly, from what they did of conspiring against 
    the first husband and breaking up his family. They should do a lot of 
    expiatory righteous deeds, as much as they can. Allah, may He be exalted, 
    says (interpretation of the meaning): “And perform As-Salat (Iqamat-as-Salat), 
    at the two ends of the day and in some hours of the night (i.e. the five 
    compulsory Salat (prayers)). Verily, the good deeds remove the evil deeds 
    (i.e. small sins). That is a reminder (an advice) for the mindful (those who 
    accept advice” [Hood 11:114]. And it was narrated from Abu Dharr (may 
    Allah be pleased with him): The Messenger of Allah (blessings and peace of 
    Allah be upon him) said to me: “Fear Allah wherever you are, and follow up a 
    bad deed with a good deed which will erase it…” Narrated by at-Tirmidhi, 
    1987; classed as hasan by al-Albaani in Sunan at-Tirmidhi. It was 
    narrated that Ka‘b ibn ‘Ujrah (may Allah be pleased with him) said: The 
    Messenger of Allah (blessings and peace of Allah be upon him) said to me: 
    “Charity extinguishes bad deeds as water extinguishes fire.” At-Tirmidhi 
    (614); classed as saheeh by al-Albaani in Sunan at-Tirmidhi. 

    After having repented, they do 
    not have to separate from one another, as is the view of the majority of 
    scholars, including the Hanafis, especially as they have children who would 
    be adversely affected by such a separation. 

    For more information, please see 
    the answer to question no. 216816

    And Allah knows best.