(200) بَابُ الْمُسْتَبَّانِ مَا قَالا فَعَلَى الأوَّلِ
The Prophet, may Allah bless him and grant him peace, said, "Do you know what calumny is?" They said, "No, Allah and His Messenger know best." He said, "Telling people what other people have said in order to create dissension between them."
Reference: Al-Adab Al-Mufrad 425
In-book reference: Book 24, Hadith 7
English translation: Book 24, Hadith 425