It was narrated from Ibn 'Umar that the Messenger of Allah (ﷺ) said:“The Muslim man has no right to spend two nights, if he has something for which a will should be made, without having a written will with him.”
حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ نُمَيْرٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ عُمَرَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَا حَقُّ امْرِئٍ مُسْلِمٍ أَنْ يَبِيتَ لَيْلَتَيْنِ وَلَهُ شَىْءٌ يُوصِي فِيهِ إِلاَّ وَوَصِيَّتُهُ مَكْتُوبَةٌ عِنْدَهُ " .
IbnMaja
The Chapters on Wills • Hadith 2699