In Islamic vocabulary, ar-Rahman and al-Raheem are the names of God.  These two Names are amongst the most frequently used Names of God in the Quran. Both are derived from the noun “mercy”, “compassion”, and “loving tenderness”.  

Ar-Rahman describes God’s attribute of being All-Merciful, and  it is used fifty seven times in Quran, while ar-Raheem describes His acts of mercy dispensed to His creation, and it is used a hundred and fourteen,  Quran said: “Say, ‘Call upon God or call upon the Most-Merciful (ar-Rahman), whichever name you call – to Him belong the most Beautiful Names….’” (Quran 17:110)>

The Prophet said: “Indeed, God is Kind, and loves kindness. He grants with kindness what He does not grant with harshness.” (Saheeh Muslim)