Al-Kāfi - Volume 7 > If a Deceased Leaves Behind Muslim and non-Muslim Heirs
Hadith #2

2- عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي نَجْرَانَ عَنْ غَيْرِ وَاحِدٍ عَنْ أَبِي عَبْدِ اللهِ (عَلَيْهِ السَّلام) فِي يَهُودِيٍّ أَوْ نَصْرَانِيٍّ يَمُوتُ وَلَهُ أَوْلادٌ مُسْلِمُونَ وَأَوْلادٌ غَيْرُ مُسْلِمِينَ فَقَالَ هُمْ عَلَى مَوَارِيثِهِمْ.

2. Ali ibn Ibrahim has narrated from his father from ibn abu Najran from more than one person who has narrated the following: “About the case of a Jew and a Christian who dies and has Muslim children and non-Muslim children, he (the Imam) said, ’The laws of inheritance apply to them.’” (Only Muslims inherit).