महायशः of great fame, वीर hero, सरथस्य with that chariot, अन्तरिक्षे sky, चरतः going, तस्य his, गतिः movement, अभ्रसम्प्लवे coursing through clouds, सूर्यस्येव, like sun न ज्ञायते cannot be known

When he moves in his chariot in the sky like the Sun coursing through clouds is difficult to know.