महात्मानस्तु मां पार्थ दैवीं प्रकृतिमाश्रिताः। भजन्त्यनन्यमनसो ज्ञात्वा भूतादिमव्ययम् ॥

mahātmānas tu māṁ pārtha daivīṁ prakṛitim āśhritāḥ bhajantyananya-manaso jñātvā bhūtādim avyayam

Verily the Mahâtmâs, O Partha, partaking of My divine nature, worship with unwavering mind, having known Me, the imperishable source of beings.

In plain words: Krishna tells Arjuna (called Partha, "son of Pritha") that great souls, called Mahatmas, share in his divine nature. They know he is the everlasting source of all beings, and they worship him with a steady mind.