Musnad Abu Ya'la al-Mawsili 241:1

Zuhayr narrated to us, Jarir narrated to us, from Isma'il, from Qays, from Khabbab, who said: We complained to the Messenger of Allah (may Allah bless him and grant him peace) while he was reclining on a mantle of his in the shade of the Ka'bah. We said: "Will you not seek victory for us?" He sat up, his face reddening, and said: "There used to be a man before you who would be taken, and a pit would be dug for him in the earth. Then a saw would be brought and placed upon his head, and he would be split in two, yet that would not turn him away from his religion. Or he would be combed with iron combs beneath his flesh, down to his bone and nerves, yet that would not turn him away from his religion. Allah will surely complete this matter until a traveler journeys from San'a to Hadramawt, fearing none but Allah the Almighty, and the wolf for his sheep. But you are impatient."