Musnad Abu Ya'la al-Mawsili 117:128

Shayban narrated to us, Ammarah ibn Zadhan narrated to us, Thabit al-Bunani narrated to us, from Anas ibn Malik, who said: The Angel of Rain asked his Lord for permission to visit the Prophet, may Allah bless him and grant him peace, and He granted him permission. It was on the day of Umm Salamah. The Prophet, may Allah bless him and grant him peace, said: "O Umm Salamah, guard the door for us; let no one enter upon us." He said: While she was at the door, al-Husayn ibn Ali came and forced his way in, opened the door, and entered. The Prophet, may Allah bless him and grant him peace, began to embrace him and kiss him. The angel said: "Do you love him?" He said: "Yes." The angel said: "Indeed, your nation will kill him. If you wish, I will show you the place where they will kill him." He said: "Yes." He said: So he took a handful from the place where he would be killed and showed it to him. It was reddish soil or dust, so Umm Salamah took it and placed it in her garment. Thabit said: We used to say that it was Karbala.