Qays bin Abi Hazim (may Allah have mercy on him) narrated from Sayyiduna Khabbab (may Allah be pleased with him), who said: I heard the Messenger of Allah (peace and blessings be upon him) while he (peace and blessings be upon him) was lying with his head resting on his cloak in the shade of the Ka'bah, and we were facing harshness from the polytheists and they had exhausted us greatly. I said: Will you not pray for us? He (peace and blessings be upon him) said: "Among those before you, a man would be seized and combed with iron combs down to what lies beneath his bone, yet that would not turn him away from his religion."
Hadith Referenceالمعجم الكبير للطبراني / باب الخاء / 3632