Musnad Ahmad 908:22

Yahya ibn Sa'id narrated to us, from Isma'il, Qays narrated to us, from Khabbab, who said: We complained to the Messenger of Allah, peace and blessings of Allah be upon him, while he was at that time reclining on a cloak in the shade of the Ka'bah. We said: "Will you not seek help from Allah for us? Will you not pray for our victory?" He said: "A man among those who were before you 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 into two halves, yet that would not turn him away from his religion. And he would be combed with iron combs, tearing away the flesh and nerves from beneath his bones, yet that would not turn him away. By Allah, this matter will certainly be completed, until a traveler journeys from Medina to Hadramawt, fearing none but Allah and the wolf for his sheep; but you are being impatient."