oṃ svabhāva-śuddhāḥ sarva-dharmāḥ svabhāva-śuddho 'ham
"Oṃ, all dharmas are pure by nature; I am pure by nature."
Note on Pronunciation
The apostrophe in the syllable 'ham is a transliteration of the Sanskrit symbol avagraha (transliterated as the nya log character in Tibetan), and is not pronounced. The word 'ham is actually the Sanskrit word aham (meaning the nominative singular pronoun "I") with the short vowel a elided (i.e. omitted) and replaced with the avagraha.