249- وبه: أن رسول الله صلى الله عليه وسلم قال: ”ما حق امرئ مسلم له شيء يوصي فيه يبيت ليلتين إلا ووصيته عنده مكتوبة.“
And with the same chain (it is narrated from Sayyiduna Ibn Umar, may Allah be pleased with them both) that the Messenger of Allah, peace and blessings be upon him, said: "If a Muslim has something to bequeath, it is not permissible for him to spend even two nights without having it written (or having it written down) with him."
Related hadith on this topic