"If he forced her, then she is free at his expense and he has to give her mistress a similar slave as a replacement. If she obeyed him in that, then she belongs to her mistress, and he has to give her mistress a similar slave as well." (Using translation from Nasāʾī 3364)
أَنَّ رَجُلًا غَشِيَ جَارِيَةَ امْرَأَتِهِ وَهُوَ فِي غَزْوٍ فَرُفِعَ ذَلِكَ إِلَى النَّبِيِّ ﷺ فَقَالَ إِنْ كَانَ اسْتَكْرَهَهَا فَهِيَ حُرَّةٌ مِنْ مَالِهِ وَعَلَيْهِ شِرَاؤُهَا لِسَيِّدَتِهَا وَإِنْ كَانَتْ طَاوَعَتْهُ فَمِثْلُهَا مِنْ مَالِهِ لِسَيِّدَتِهَا