(1) باب الْكَرَاهِيَةِ فِي تَأْخِيرِ الْوَصِيَّةِ
It was narrated that Ibn 'Umar said:
"The Messenger of Allah said: 'It is not befitting for a Muslim who has anything concerning which a will should be made, to abide for two nights without having a written will with him.'"
Reference: Sunan an-Nasa'i 3615
In-book reference: Book 30, Hadith 5
English translation: Vol. 4, Book 30, Hadith 3645