Paritraanaaya Saadhunaam

परित्राणाय साधूनां

विनाशाय च दुष्कृताम् ।

धर्म संस्थापनार्थाय

सम्भवामि युगे युगे

paritrāṇāya sādhūnāṁ

vināśāya ca duṣkr̥tām ।
dharmasaṁsthāpanārthāya

sambhavāmi yugē yugē

This shloka is from Bhagavad Gita, Chapter 4, Verse 8.

This was said by Bhagwan Sri Krishna to Arjuna.

Meaning:

For the protection of the virtuous, for the annihilation of the miscreants, and for reestablishing Dharma (righteousness) on a firm footing. I make Myself appear from age to age.