Ar-Rahman, Ar-Raheem (The Most Compassionate, The Most Merciful)
Allah opens the Qur’an with His name, and then teaches us two additional names, “Ar-Rahman” and “Ar-Raheem.” What do these names mean?
The name “Ar-Rahman” communicates Allah's mercy toward all creation — believers and non-believers alike. Even those who disobey Him and worship other than Him still receive His mercy through food, water, air, and everything sustaining life.
The name “Ar-Raheem” refers to Allah's mercy specifically for the believers. Some scholars are of the opinion that this mercy is reserved for them on the Day of Judgment, though one opinion holds that it also applies to this worldly life.
When Allah describes the Prophet ﷺ in verse 128 of Surah at-Tawbah, He says the Prophet is "bil-mu'mineena ra'oofur raheem,” which means, “he is to the believers, full of kindness and mercy.”