Al-Kāfi

Hadith 2207
christians-jews
7ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ عَبْدِ الرَّحْمَنِ بْنِ الْحَجَّاجِ قَالَ قُلْتُ لأبِي الْحَسَنِ مُوسَى (عَلَيهِ السَّلام) أَ رَأَيْتَ إِنِ احْتَجْتُ إِلَى مُتَطَبِّبٍ وَهُوَ نَصْرَانِيٌّ أُسَلِّمُ عَلَيْهِ وَأَدْعُو لَهُ قَالَ نَعَمْ إِنَّهُ لا يَنْفَعُهُ دُعَاؤُكَ.
7. Ali ibn Ibrahim has narrated from his father from Ibn Abi ‘Umayr from ‘Abd al- Rahman ibn al-Hajjaj who has said the following: ‘‘Once I asked abu al-Hassan Musa (a.s.) ‘If I needed to visit a Christian physician, can I offer the greeting of peace and pray for him?’ The Imam said, ‘Yes, but your prayer will not benefit him.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī