Mustadrak al-Hakim — Hadith 5782

It is narrated from Abdullah bin Salimah that he said: On the day of Siffin I saw Sayyiduna Ammar bin Yasir (may Allah be pleased with him). He was a tall, brown-complexioned old man holding a spear in his hand, and his hand was trembling (because of old age). He said: "By the One in whose Hand is my soul! I have fought with this spear alongside the Messenger of Allah (peace and blessings be upon him) three times, and this is the fourth. And by the One in whose Hand is my soul! Even if these people were to beat us until they drove us as far as the palm branches of Hajar, we would still know that our righteous people are upon the truth and that they are upon misguidance."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), and they did not record it.