Musannaf Ibn Abi Shaybah

Hazrat Harith (may Allah be pleased with him) bin Hassan narrates that I arrived in Madinah Munawwarah and the Holy Prophet (peace and blessings be upon him) was seated on the pulpit, and Hazrat Bilal (may Allah be pleased with him) was standing before him with a sword hanging by his side. Suddenly, black flags appeared. I inquired, "Who are these?" People informed me that Hazrat Amr bin Aas (may Allah be pleased with him) has returned from a battle.