(Al-Baqara) 2 : 226
لِلَّذِينَ يُؤْلُونَ مِنْ نِسَائِهِمْ تَرَبُّصُ أَرْبَعَةِ أَشْهُرٍ ۖ فَإِنْ فَاءُوا فَإِنَّ اللَّهَ غَفُورٌ رَحِيمٌ
For those who take an oath for abstaining with their women, women should wait for four months; if they return, then indeed Lord Allah is the Oft-forgiving, Merciful.