It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: There are two phrases which are light on the tongue, heavy on the scales of deeds, and beloved to the Most Merciful: Subhan Allah wa bihamdihi, Subhan Allah al-Azeem.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 7167