Ibrahim al-Nakha'i إبراهيم النخعي · The Book of Wills

"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.'"

"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."

(The same) was narrated from Ibn 'Awn, from Nafi', from Ibn 'Umar.