The Book Pertaining to the Remembrance of Allah, Supplication, Repentance and Seeking Forgiveness (Kitab Al-Dhikr)
Muslim :: Book 35 : Hadith 6587
Abu Dharr reported that Allah's Messenger (may peace be upon him) said: Should I not inform you about the words liked most by Allah? I said: Allah's Mes- senger, do inform me about the words liked most by Allah. He said: Verily, the words liked most by Allah are:" hallowed be Allah and praise is due to Him."