Al Baqarah, 226 Ayah
2:226
لِّلَّذِينَ يُؤۡلُونَ مِن نِّسَآئِهِمۡ تَرَبُّصُ أَرۡبَعَةِ أَشۡهُرٖۖ فَإِن فَآءُو فَإِنَّ ٱللَّهَ غَفُورٞ رَّحِيمٞ ٢٢٦
Lilladhīna Yu'ulūna Min Nisā'ihim Tarabbuşu 'Arba`ati 'Ash/hurin ۖ Fa'in Fā'ū Fa'inna Al-Laha Ghafūrun Raĥīmun
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, Allah is Forgiving and Merciful.