ENOfficial
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.”
Source: sunnah.com
Other translations
Arabic
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 " .
sunnah.com