One day I was riding behind the Messenger of Allah ﷺ when he said, "Young man, let me teach you some words. Be mindful of Allah, and He will protect you. Be mindful of Allah, and you will find Him before you. When you ask, ask Allah. When you seek help, seek help from Allah. Know that if the entire nation were to gather together to benefit you with something, they could not benefit you except with what Allah has already written for you. And if they were to gather together to harm you with something, they could not harm you except with what Allah has already written against you. The pens have been lifted and the pages have dried."
كنت خلف رسول الله ﷺ يوما، فقال: يا غلام إني أعلمك كلمات: احفظ الله يحفظك، احفظ الله تجده تجاهك، إذا سألت فاسأل الله، وإذا استعنت فاستعن بالله، واعلم أن الأمة لو اجتمعت على أن ينفعوك بشيء لم ينفعوك إلا بشيء قد كتبه الله لك، ولو اجتمعوا على أن يضروك بشيء لم يضروك إلا بشيء قد كتبه الله عليك، رفعت الأقلام، وجفت الصحف.
Tirmidhi (2516) narrated it from Ahmad bin Muhammad bin Musa, who said, Abdullah bin Mubarak informed us, Layth bin Saad and Ibn Lahia informed us, from Qays bin Hajjaj. H. Also, Abdullah bin Abdul-Rahman narrated to us, Abu Walid informed us, Layth bin Saad narrated to us, Qays bin Hajjaj narrated to me, the meaning being the same, from Hanash Sanani, from Ibn Abbas, and he related it.Tirmidhi said, "hasan sahih."Ibn Lahia has been corroborated. Ibn Mubarak narrated it from him, and Ibn Wahb likewise narrated it from him in Qadar (28). Firyabi narrated it in Qadar (153), and Bayhaqi in Qada wal-Qadar (2/523) narrated it from Layth alone, with this chain.I say, its chain is hasan because of Qays bin Hajjaj, who is Kalai Silafi, and the discussion about him is set out at length in the book of Iman.