When you have divorced women and they have reached the end of their waiting period, do not prevent them from re-marrying their ex-husbands if they come to an honourable agreement. This is enjoined on whoever has faith in Allah and the Last Day. This is purer and more dignifying for you. Allah knows and you do not know.
— Dr. Mustafa Khattab, the Clear Quran
And when you divorce women1 and they have fulfilled their term, do not prevent them from remarrying their [former] husbands if they [i.e., all parties] agree among themselves on an acceptable basis. That is instructed to whoever of you believes in Allah and the Last Day. That is better for you and purer, and Allah knows and you know not.
— Saheeh International