Al Mujadila Ayah 3
وَٱلَّذِينَ يُظَـٰهِرُونَ مِن نِّسَآئِهِمْ ثُمَّ يَعُودُونَ لِمَا قَالُواْ فَتَحْرِيرُ رَقَبَةٍ مِّن قَبْلِ أَن يَتَمَآسَّاۚ ذَٲلِكُمْ تُوعَظُونَ بِهِۦۚ وَٱللَّهُ بِمَا تَعْمَلُونَ خَبِيرٌ ٣
Those who divorce their wives in this manner, then ?wish to? retract what they said, must free a slave before they touch each other. This ?penalty? is meant to deter you. And Allah is All-Aware of what you do.