It was narrated from Ibn 'Umar that the Prophet ﷺ said:
“The Muslim man has no right to spend two nights, if he has something for which will should be made, without having a written will with him.”

حَدَّثَنَا مُحَمَّدُ بْنُ مَعْمَرٍ، حَدَّثَنَا رَوْحُ بْنُ عَوْفٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، عَنِ النَّبِيِّ ﷺ قَالَ " مَا حَقُّ امْرِئٍ مُسْلِمٍ يَبِيتُ لَيْلَتَيْنِ وَلَهُ شَىْءٌ يُوصِي بِهِ إِلاَّ وَوَصِيَّتُهُ مَكْتُوبَةٌ عِنْدَهُ " .