(401) بَابُ الأرْوَاحُ جُنُودٌ مُجَنَّدَةٌ
'A'isha said, "I heard the Messenger of Allah, may Allah blesshim and grant him peace, say, 'The arwah are a massed army. When they alreadyknow each other, they are friendly. When they do not know each other, theydisagree.'"
Reference: Al-Adab Al-Mufrad 900
In-book reference: Book 38, Hadith 13
English translation: Book 38, Hadith 900