Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Between every two Muslims there is a veil from Allah Almighty. When one of them says something foul to the other, that veil is torn; and when he says, 'O disbeliever!', then one of the two has disbelieved."
Al-Tabarani recorded it, and al-Bazzar recorded it in abridged form. Its chain contains Yazid bin Abi Ziyad, whose narrations are hasan (good), though there is a difference of opinion about this narrator. The remaining narrators of al-Bazzar are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 13014
Hadith Gradingمحدثین:إسنادہ حسن
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (193/18) ، أخرجه مسند البزار برقم: 1869، وأخرجه المعجم الكبير للطبراني برقم: 10544»