यदादित्यगतं तेजो जगद्भासयतेऽखिलम्। यच्चन्द्रमसि यच्चाग्नौ तत्तेजो विद्धि मामकम् ॥

yad āditya-gataṁ tejo jagad bhāsayate ’khilam yach chandramasi yach chāgnau tat tejo viddhi māmakam

That splendour issuing from the sun that enlighteneth the whole world, that which is in the moon and in fire, that splendour know as from Me.

In plain words: Krishna says the light of the sun that lights up the whole world, and the light in the moon and in fire, all come from him.