It is narrated from Hazrat Harith (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said to me: When you have performed the Fajr prayer, before speaking to anyone, say seven times: "Allahumma ajirni min an-nar" (O Allah, save me from the Fire). If you die during this time, Allah Almighty will decree protection from Hell for you. Similarly, when you have performed the Maghrib prayer, before speaking to anyone, say seven times: "Allahumma inni as'aluka al-jannah, Allahumma ajirni min an-nar" (O Allah, I ask You for Paradise, O Allah, save me from the Fire). If you die that night, Allah Almighty will decree protection from Hell for you.

It is narrated from Hazrat Harith (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) wrote a will for him (Harith, may Allah be pleased with him) in the name of the rulers who would come after him, and he also sealed it.