Al-Kāfi - Volume 6 > Slaughtering by the People of the Book
Hadith #3

وَ عَنْهُ عَنْ حَنَانٍ قَالَ قُلْتُ لِأَبِي عَبْدِ اللَّهِ ( عليه السلام ) إِنَّ الْحُسَيْنَ بْنَ الْمُنْذِرِ رَوَى عَنْكَ أَنَّكَ قُلْتَ إِنَّ الذَّبِيحَةَ بِالِاسْمِ وَ لَا يُؤْمَنُ عَلَيْهَا إِلَّا أَهْلُهَا فَقَالَ إِنَّهُمْ أَحْدَثُوا فِيهَا شَيْئاً لَا أَشْتَهِيهِقَالَ حَنَانٌ فَسَأَلْتُ نَصْرَانِيّاً فَقُلْتُ لَهُ أَيُّ شَيْ‏ءٍ تَقُولُونَ إِذَا ذَبَحْتُمْ فَقَالَ نَقُولُ بِاسْمِ الْمَسِيحِ .

3. It is narrated from the narrator of the previous Hadith from Hanan who has said the following: “I once said to abu ‘Abd Allah, ‘Alayhi al-Salam, ‘Al-Husayn ibn al-Mundhir has narrated from you that you have said, “Slaughtering is by name and you cannot trust for it in (slaughtering) except the people of the name.’” He (the Imam) said, ‘They have invented in it something that I do not like.’ Hanan has said, ‘I asked a Christian about what they say when slaughtering.’ He said, ‘We say, “In the name of al-Masih.’””