The Messenger of Allah ﷺ said, "No one should pass three nights without having his will written down."Ibn Umar said, "From that moment on, I never spent a single night without my will being kept ready beside me."
حدثنا معتمر سمعت بردا عن الزهري عن سالم
قال رسول الله ﷺ لا يبيت أحد ثلاث ليال إلا ووصيته مكتوبة قال فما بت من ليلة بعد إلا ووصيتي عندي موضوعة
Its isnad is sahih. Burd is Ibn Sinan Shami, and he is trustworthy. Ibn Main, Duhaym, Nasai, and others declared him trustworthy. Ahmad said, "He is sound in hadith." Yazid bin Zuray said, "I have not seen a Syrian more trustworthy than Burd." Bukhari mentioned him in Kabir, 1/2/134.Salim is Ibn Abdullah bin Umar, a well known trustworthy imam and an authority. Malik said, "There was no one in the time of Salim bin Abdullah who more resembled the righteous people of old in asceticism, excellence, and simplicity of life than he did."This hadith was narrated by the group of major hadith compilers with the same meaning. See Muntaqa, 3271.