Al-Kāfi

Hadith 1405
marriage
5- عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنْ مُحَمَّدِ بْنِ أَبِي عُمَيْرٍ عَنْ حَمَّادٍ عَنِ الْحَلَبِيِّ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) قَالَ سُئِلَ عَنِ الرَّجُلِ يَكُونُ لَهُ الْخَادِمُ وَلَدَ زِنًى عَلَيْهِ جُنَاحٌ أَنْ يَطَأَهَا قَالَ لا وَإِنْ تَنَزَّهَ عَنْ ذَلِكَ فَهُوَ أَحَبُّ إِلَيَّ.
5. Ali ibn Ibrahim has narrated from his father from Muhammad Ibn Abi ‘Umayr from Hammad from al-Halabiy who has said the following: “Once abu ‘Abd Allah (a.s.), was asked about the case of a man who has a servant born out of wedlock; if he can go to bed with her. He (the Imam) said, ‘No, if he stays clean of that, it is more likeable to me.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī