Musnad Ahmad Hadith 21073

It is narrated from Khabbab (may Allah be pleased with him) that once we presented ourselves in the court of the Prophet. The Prophet (ﷺ) was sitting at that time in the shade of the Ka'bah, reclining on his cloak. We said, "O Messenger of Allah, pray to Allah for us and seek help for us." Upon hearing this, the color of the blessed face of the Prophet (ﷺ) turned red and he said, "For the people before you, pits were dug as a punishment for accepting the religion, and saws were placed on their heads and their heads were split open, but this did not turn them away from their religion. In the same way, iron combs were used to tear the flesh and muscles from behind their bones, but even this pain did not turn them away from their religion. And Allah will surely complete this religion, until a rider will travel between Sana'a and Hadramaut and will fear none but Allah, or the attack of a wolf on his sheep. But you people are hasty."