Sulaiman al-A'mash الأعمش / سليمان بن مهران · Wills (Kitab Al-Wasaya)

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.

A man asked him (the Prophet): Messenger of Allah, what are the grave sins? He replied: They are nine. He then mentioned the tradition to the same effect. This version adds: "And disobedience to the Muslim parents, and to violate the sacred House, your qiblah (direction of prayer), in your life and after death.