The Book of Wills
30/1. Chapter:
It Is Disliked To Delay Making A Will
Sunan an-Nasai
أَخْبَرَنَا أَحْمَدُ بْنُ يَحْيَى بْنِ الْوَزِيرِ بْنِ سُلَيْمَانَ، قَالَ سَمِعْتُ ابْنَ وَهْبٍ، قَالَ أَخْبَرَنِي يُونُسُ، وَعَمْرُو بْنُ الْحَارِثِ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِيهِ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " مَا حَقُّ امْرِئٍ مُسْلِمٍ لَهُ شَىْءٌ يُوصَى فِيهِ فَيَبِيتُ ثَلاَثَ لَيَالٍ إِلاَّ وَوَصِيَّتُهُ عِنْدَهُ مَكْتُوبَةٌ ".
It was narrated from Salim bin 'Abdullah, from his father, that the Messenger of Allah said: "It is not right for a Muslim who has anything concerning which a will should be made, to abide for more than three nights without having a written will with him."
Reference : Sunan an-Nasa'i 3619In-book reference : Book 30, Hadith 9English translation : Vol. 4, Book 30, Hadith 3649