Al-Kāfi - Volume 5 > Marriage with a Woman and ‘Umm Walad of Her Father
Hadith #3

3- أَبُو عَلِيٍّ الأشْعَرِيُّ عَنِ الْحَسَنِ بْنِ عَلِيٍّ الْكُوفِيِّ عَنْ عَبْدِ اللهِ بْنِ جَبَلَةَ عَنْ إِسْحَاقَ بْنِ عَمَّارٍ عَنْ أَبِي الْحَسَنِ (عَلَيْهِ السَّلام) قَالَ سَأَلْتُهُ عَنِ الرَّجُلِ يَهَبُ لِزَوْجِ ابْنَتِهِ الْجَارِيَةَ وَقَدْ وَطِئَهَا أَيَطَؤُهَا زَوْجُ ابْنَتِهِ قَالَ لا بَأْسَ بِهِ.

3. Abu Ali al-Ash’ariy has narrated from al-Hassan ibn Ali al-Kufiy ibn Jabalah from Ishaq ibn ‘Ammar who has said the following: “I once asked abu al-Hassan, ‘Alayhi al-Salam, about the case of a man who gives as a gift his slave- girl with whom he has gone to bed, to his son in-law; if his son in-law can go to bed with this slave- girl. He (the Imam) said, ‘It is not unlawful.’”