Dua for Protection from Hellfire
اللَّهُمَّ أَجِرْنِي مِنَ النَّارِ
Allahumma ajirni min an-nar.
"O Allah, save me from the Fire."
Sunan Abi Dawud 5079
Spiritual Benefits
According to Hadith, whoever recites this seven times after Fajr and Maghrib prayers, and dies that day or night, Allah will write for them protection from the Hellfire.
When Should I Say This Dua?
Recite 7 times immediately after the Fajr and Maghrib prayers, before speaking to anyone.
Proper Etiquette (Sunnah)
Recite with a genuine fear of the Fire and hope in Allah's mercy.