'Abdullah ibn 'Amr reported that the Prophet, may Allah bless him and grant him peace, said, "It is not lawful for a man to separate two people except with the permission of both of them."  

أَنَّ النَّبِيَّ ﷺ قَالَ لاَ يَحِلُّ لِرَجُلٍ أَنْ يُفَرِّقَ بَيْنَ اثْنَيْنِ إِلا بِإِذْنِهِمَا