Sunan Abi Dawud 2862
سنن أبي داود#2862Sahihحَدَّثَنَا مُسَدَّدُ بْنُ مُسَرْهَدٍ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ عُبَيْدِ اللَّهِ، حَدَّثَنِي نَافِعٌ، عَنْ عَبْدِ اللَّهِ، - يَعْنِي ابْنَ عُمَرَ - عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " مَا حَقُّ امْرِئٍ مُسْلِمٍ لَهُ شَىْءٌ يُوصِي فِيهِ يَبِيتُ لَيْلَتَيْنِ إِلاَّ وَوَصِيَّتُهُ مَكْتُوبَةٌ عِنْدَهُ " .
Narrated 'Abdullah bin 'Umar:The Messenger of Allah (ﷺ) as saying: It is the duty of a Muslim man who has something which is to be given as bequest not to have it for two nights without having his will written regarding it
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 18:1