Bhagavad Gita, Chapter 11, Verse 37

And why should they not, O Great-souled One, bow to You, greater than, and the Primal Cause of even Brahmâ, O Infinite Being, O Lord of the Devas, O Abode of the universe? You are the Imperishable, the Being and the non-Being, as well as That which is Beyond them.

Even the being usually credited with creating everything is placed here beneath something greater still.

Naming Brahma directly and then ranking Krishna above him makes a real, specific claim rather than a vague superlative. The scale keeps expanding past what Arjun had already accepted.