Surah Al-Baqarah, Verse 226

لِّلَّذِينَ يُؤۡلُونَ مِن نِّسَآئِهِمۡ تَرَبُّصُ أَرۡبَعَةِ أَشۡهُرٖۖ فَإِن فَآءُو فَإِنَّ ٱللَّهَ غَفُورٞ رَّحِيمٞ٢٢٦

lilladhīna yu'lūna min nisāihim tarabbuṣu arbaʿati ashhurin fa-in fāū fa-inna l-laha ghafūrun raḥīmun

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