Messenger of Allah ﷺ said, "It is not permissible for any Muslim who has something to will to stay for two nights without having his last will and testament written and kept ready with him."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَا حَقُّ امْرِئٍ مُسْلِمٍ لَهُ شَىْءٌ يُوصِي فِيهِ يَبِيتُ لَيْلَتَيْنِ إِلاَّ وَوَصِيَّتُهُ مَكْتُوبَةٌ عِنْدَهُ