Ubaydah (may Allah have mercy on him) said: I asked Sayyiduna Ali (may Allah be pleased with him) about the slaughtered animals of the Christians of Banu Taghlib, and he said: Do not eat their slaughtered animals, for nothing of their religion has remained with them except wine.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجزية / 18799