Al-Ahzab 33:52

لَّا يَحِلُّ لَكَ ٱلنِّسَآءُ مِنۢ بَعْدُ وَلَآ أَن تَبَدَّلَ بِهِنَّ مِنْ أَزْوَٰجٍۢ وَلَوْ أَعْجَبَكَ حُسْنُهُنَّ إِلَّا مَا مَلَكَتْ يَمِينُكَ ۗ وَكَانَ ٱللَّهُ عَلَىٰ كُلِّ شَىْءٍۢ رَّقِيبًۭا

It is not lawful for thee (to marry more) women after this, nor to change them for (other) wives, even though their beauty attract thee, except any thy right hand should possess (as handmaidens): and Allah doth watch over all things.