Sunan an-Nasa'i 3615
سنن النسائي#3615SahihIt 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
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 30:5