The regulation of oaths (aymān)

لِّلَّذِينَ يُؤْلُونَ مِن نِّسَآئِهِمْ تَرَبُّصُ أَرْبَعَةِ أَشْهُرٍ ۖ فَإِن فَآءُو فَإِنَّ 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, Allāh is Forgiving and Merciful.