Surah Al-Baqarah, ayah 226

2:226

لِّلَّذِينَ يُؤۡلُونَ مِن نِّسَآئِهِمۡ تَرَبُّصُ أَرۡبَعَةِ أَشۡهُرٖۖ فَإِن فَآءُو فَإِنَّ ٱللَّهَ غَفُورٞ رَّحِيمٞ ٢٢٦

Llilladhīna yu'lūna min nisā'ihim tarabbusu arba'ati ashhurin fa in fā'ū fa innallāha ghafūrur rahīm

For those who swear not to have sexual relations with their wives85 is a waiting time of four months, but if they return [to normal relations] - then indeed, Allāh is Forgiving and Merciful.

Footnotes

85 Without divorcing them. By such an oath the woman is deprived of her right in marriage but is not free to marry another. She may not be kept in such a condition beyond the four-month limit.