He used to teach his sons these words just as a teacher instructs young boys in writing, saying that the Messenger of Allah ﷺ would seek refuge through them after the prayer, "Allah, I seek refuge in You from cowardice, I seek refuge in You from being returned to the most feeble stage of life, I seek refuge in You from the trials of this world, and I seek refuge in You from the punishment of the grave."In another narration he added, "And I seek refuge in You from miserliness."
أنه كان يعلم بنه هؤلاء الكلمات، كما يعلم المعلم الغلمان الكتابة ويقول: إن رسول الله ﷺ كان يتعوذ منهن دبر الصلاة: اللهم أعوذ بك من الجبن، وأعوذ بك أن أرد إلى أرذل العمر، وأعوذ بك من فتنة الدنيا، وأعوذ بك من عذاب القبر. وزاد في رواية: وأعوذ بك من البخل.
Bukhari narrated it in the Book of Jihad and Campaigns (2822) via Abu Awana, from Abdul-Malik bin Umayr, who said, I heard Amr bin Maymun Awdi say, Saad was, and then he mentioned the hadith. Bukhari also narrated it via Shuba (6365, 6370), Zaida (6374), and Ubayda bin Humayd (6390), all of them from Abdul-Malik bin Umayr, from Musab bin Saad, from his father, but they did not mention that this was after the prayer, dubur here meaning the end of the prayer before the tasleem.