From Sahih Bukhari (Hadith 7563):
Narrated Abu Huraira:The Prophet (ﷺ) said, "(There are) two words which are dear to the Beneficent (Allah) and very light (easy) for the tongue (to say), but very heavy in weight in the balance. They are: ''Subhan Allah wa-bi hamdihi'' and ''Subhan Allah Al-`Azim." (see Hadith)
Reference: Bukhari 7563