त्वमादिदेवः पुरुषः पुराण स्त्वमस्य विश्वस्य परं निधानम्। वेत्तासि वेद्यं च परं च धाम त्वया ततं विश्वमनन्तरूप ॥

tvam ādi-devaḥ puruṣhaḥ purāṇas tvam asya viśhvasya paraṁ nidhānam vettāsi vedyaṁ cha paraṁ cha dhāma tvayā tataṁ viśhvam ananta-rūpa

First of the Gods, most ancient Man Thou art. Supreme receptacle of all that lives; Knower and known, the dwelling-place on high; In Thy vast Form the universe is spread.

In plain words: Arjuna praises Krishna as the first of the gods and the most ancient being. Everything that lives rests in him, he knows all and is what is known, and the whole universe is spread out in his form.