(The narrator Isma'il said: I think ash-Sha'bi attributed this tradition to the Prophet) The Prophet ﷺ said: Curse be upon the one who marries a divorced woman with the intention of making her lawful for her former husband and upon the one for whom she is made lawful.  

إِسْمَاعِيلُ وَأُرَاهُ قَدْ رَفَعَهُ إِلَى النَّبِيِّ ﷺ أَنَّ النَّبِيَّ ﷺ قَالَ لَعَنَ اللَّهُ الْمُحَلِّلَ وَالْمُحَلَّلَ لَهُ  

The aforesaid tradition has also been transmitted by ‘Ali through a different chain of narrators from the Prophet ﷺ to the same effect.  

عَنْ رَجُلٍ مِنْ أَصْحَابِ النَّبِيِّ ﷺ قَالَ فَرَأَيْنَا أَنَّهُ عَلِيٌّ عَلَيْهِ السَّلاَمُ عَنِ النَّبِيِّ ﷺ بِمَعْنَاهُ