concerning the Verse: 'Do not prevent them' (2.232) Ma'qil bin Yasar told me that it was revealed in his connection. He said, "I married my sister to a man and he divorced her, and when her days of 'Idda (three menstrual periods) were over, the man came again and asked for her hand, but I said to him, 'I married her to you and made her your bed (your wife) and favored you with her, but you divorced her. Now you come to ask for her hand again? No, by Allah, she will never go back to you (again)!' That man was not a bad man and his wife wanted to go back to him. So Allah revealed this Verse: 'Do not prevent them.' (2.232) So I said, 'Now I will do it (let her go back to him), O Messenger of Allah ﷺ."So he married her to him again. (Using translation from Bukhārī 5130)   

كُنْتُ زَوَّجْتُ أُخْتًا لِي مِنْ رَجُلٍ فَطَلَّقَهَا حَتَّى إِذَا انْقَضَتْ عِدَّتُهَا جَاءَ فَخَطَبَهَا فَقُلْتُ لَهُ زَوَّجْتُكَ وَأَفْرَشْتُكَ وَأَكْرَمْتُكَ فَطَلَّقْتَهَا ثُمَّ جِئْتَ تَخْطُبُهَا لَا وَاللهِ لَا تَعُودُ إِلَيْهَا أَبَدًا قَالَ وَكَانَ رَجُلًا لَا بَأْسَ بِهِ وَكَانَتِ امْرَأَتُهُ تُرِيدُ أَنْ تَرْجِعَ إِلَيْهِ قَالَ فَأَنْزَلَ اللهُ ﷻ هَذِهِ الْآيَةَ فَقُلْتُ الْآنَ أَفْعَلُ يَا رَسُولَ اللهِ فَزَوَّجْتُهَا إِيَّاهُ  

[Machine] The Messenger of Allah ﷺ said: Any woman who is married without the permission of her guardians, her marriage is invalid, her marriage is invalid, her marriage is invalid. If a man has intercourse with her, she is entitled to her dowry for what he has done to her. And if they dispute, then the ruler is the guardian of one who has no guardian. And it is narrated from Mujalid from Al-Sha'bi from Ali and Abdullah and Shurayh, they said: There is no marriage without a guardian, except for a woman whose guardian hinders her, so she goes to the ruler or to the judge. And it is also narrated from Ziyad bin Al-Aqqa that Uthman bin Affan wrote: If the father is competent, then tell him to marry her. If he refuses, then marry her and ask for Allah's guidance. And Allah knows best.  

رَسُولَ اللهِ ﷺ يَقُولُ أَيُّمَا امْرَأَةٍ نُكِحَتْ بِغَيْرِ إِذْنِ مَوَالِيهَا فَنِكَاحُهَا بَاطِلٌ فَنِكَاحُهَا بَاطِلٌ فَنِكَاحُهَا بَاطِلٌ فَإِنْ أَصَابَهَا فَلَهَا مَهْرُهَا بِمَا أَصَابَهَا وَإِنْ تَشَاجَرُوا فَالسُّلْطَانُ وَلِيُّ مَنْ لَا وَلِيَّ لَهُ وَرُوِّينَا عَنْ مُجَالِدٍ عَنِ الشَّعْبِيِّ عَنْ عَلِيٍّ وَعَبْدِ اللهِ وَشُرَيْحٍ قَالُوا لَا نِكَاحَ إِلَّا بِوَلِيٍّ إِلَّا امْرَأَةً يَعْضِلُهَا الْوَلِيُّ فَتَأْتِي السُّلْطَانَ أَوِ الْقَاضِيَ وَعَنْ زِيَادِ بْنِ عِلَاقَةَ قَالَ كَتَبَ عُثْمَانُ بْنُ عَفَّانَ ؓ إِنْ كَانَ كُفُؤًا فَقُولُوا لِأَبِيهَا يُزَوِّجُهَا فَإِنْ أَبَى فَزَوِّجُوهَا وَبِاللهِ التَّوْفِيقُ وَاللهُ أَعْلَمُ