Al-Baqarah 2:230
فَإِن طَلَّقَهَا فَلَا تَحِلُّ لَهُ مِن بَعْدُ حَتَّىٰ تَنكِحَ زَوْجًا غَيْرَهُ ۗ فَإِن طَلَّقَهَا فَلَا جُنَاحَ عَلَيْهِمَا أَن يَتَرَاجَعَا إِن ظَنَّا أَن يُقِيمَا حُدُودَ اللَّهِ ۗ وَتِلْكَ حُدُودُ اللَّهِ يُبَيِّنُهَا لِقَوْمٍ يَعْلَمُونَ ٢٣٠
Fain tallaqaha fala tahillu lahu min baAAdu hatta tankiha zawjan ghayrahu fain tallaqaha fala junaha AAalayhima an yatarajaAAa in thanna an yuqeema hudooda Allahi watilka hudoodu Allahi yubayyinuha liqawmin yaAAlamoona
“And if he hath divorced her (the third time), then she is not lawful unto him thereafter until she hath wedded another husband. Then if he (the other husband) divorce her it is no sin for both of them that they come together again if they consider that they are able to observe the limits of Allah. These are the limits of Allah. He manifesteth them for people who have knowledge.” (2:230)