From his father, who said: "I asked the Prophet ﷺ about the food of the Christians. He ﷺ said: 'Do not allow food to put uneasiness in your chest similar to the doubts of Christianity about it."  

سَأَلْتُ النَّبِيَّ ﷺ عَنْ طَعَامِ النَّصَارَى فَقَالَ لاَ يَتَخَلَّجَنَّ فِي صَدْرِكَ طَعَامٌ ضَارَعْتَ فِيهِ النَّصْرَانِيَّةَ  

Another Chain with similar chain.  

عَنِ النَّبِيِّ ﷺ مِثْلَهُ  

Another chain with similar narration. This is acted upon according to the people of knowledge regarding the permission for the food of the People of the Book.  

عَنِ النَّبِيِّ ﷺ مِثْلَهُ وَالْعَمَلُ عَلَى هَذَا عِنْدَ أَهْلِ الْعِلْمِ مِنَ الرُّخْصَةِ فِي طَعَامِ أَهْلِ الْكِتَابِ