2:226
لِّ لَّذِينَ يُؤْلُ ونَ مِن نِّسَآئِ هِمْ تَرَبُّصُ أَرْبَعَةِ أَشْهُرٍ فَ إِن فَآءُ و فَ إِنَّ ٱللَّهَ غَفُورٌ رَّحِيمٌ
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.