Hadith: Among those who came before you, a man would be seized and held in a pit dug for him in the ground, and he would be sawed into two halves from his head, and his flesh would be torn away from his bones with iron combs, and none of this would turn him away from his religion

عن أبي عبد الله خباب بن الأرت رضي الله عنه قال: شكونا إلى رسول الله صلى الله عليه وسلم وهو مُتَوَسِّدٌ بُرْدَةً له في ظِلِّ الكعبة، فقلنا أَلاَ تَسْتَنْصِرُ لنا، ألا تدعو الله لنا؟ فقال: «قد كان من قبلكم يُؤخذ الرجل فيُحفر له في الأرض، فيُجعل فيها، ثمَّ يُؤتى بالمِنْشَارِ فيوضع على رأسه فيُجعل نصفين، ويُمشط بأمشاطِ الحديد ما دون لحمه وعظمه، ما يَصُدُّهُ ذلك عن دينه، والله لَيُتِمَّنَّ الله هذا الأمر حتى يسير الراكب من صنعاء إلى حضرموت لا يخاف إلا الله والذئب على غَنَمِه، ولكنكم تستعجلون». وفي رواية: «هو مُتَوَسِّدٌ بُرْدَةً، وقد لقينا من المشركين شدة».
[صحيح] - [رواه البخاري]

Abu ‘Abdullāh Khabbāb ibn al-Aratt (may Allah be pleased with him) reported: We complained to the Messenger of Allah (may Allah's peace and blessings be upon him) while he was lying in the shade of the Ka‘bah, placing his cloak under his head. We said: "Will you not supplicate for our victory (over our opponents)? Will you not invoke Allah for us?" He replied: "Among those who came before you, a man would be seized and held in a pit dug for him in the ground, and he would be sawed into two halves from his head, and his flesh would be torn away from his bones with iron combs, and none of this would turn him away from his religion. By Allah, Allah will bring this matter (Islam) to its completion until the traveler will walk from Sana'a to Hadramaut fearing none except Allah and the wolf for his sheep, but you are rushing things." In another narration: "Having made a pillow from his cloak, and we had faced much persecution from the polytheists."
Sahih/Authentic. - [Al-Bukhari]

Explanation

In this Hadīth, Khabbāb (may Allah be pleased with him) tells the story of the suffering that the Muslims faced from the disbelievers of the Quraysh in Makkah. They came complaining to the Prophet (may Allah's peace and blessings be upon him) while he was lying in the shade of the Ka‘bah placing his head on his cloak. The Prophet (may Allah's peace and blessings be upon him) explained that those who lived before us experienced severer trials regarding their religion. A pit would be dug for one of them and he would be thrown into it; then a saw would be brought to the top of his head and he would be sawed into two halves; and his flesh would be torn away from his bones with iron combs, which was extreme suffering. Then he swore that Allah, the Almighty, would complete this matter, meaning that He would complete the message of Islam that the Messenger (may Allah's peace and blessings be upon him) had brought. This would be done in such a way that the one traveling from Sana'a to Hadramaut would fear none except Allah and the wolf for his sheep. Then he guided his noble Companions to stop rushing things, saying: "But you are rushing things," meaning: have patience and await relief from Allah, for Allah will surely complete this matter, and things went just as the Prophet (may Allah's peace and blessings be upon him) swore they would go.