You are air, fire, water, and You are the moon! You are the supreme controller and the grandfather. Thus I offer my respectful obeisances unto You a thousand times, and again and yet again! BG 11.39 - 1972

Expressions researched:
"You are air, fire, water, and You are the moon! You are the supreme controller and the grandfather. Thus I offer my respectful obeisances unto You a thousand times, and again and yet again"

Bhagavad-gita As it is

BG Chapters 7 - 12

You are air, fire, water, and You are the moon! You are the supreme controller and the grandfather. Thus I offer my respectful obeisances unto You a thousand times, and again and yet again!

BG 11.39 (1972), Translation and Purport

You are air, fire, water, and You are the moon! You are the supreme controller and the grandfather. Thus I offer my respectful obeisances unto You a thousand times, and again and yet again!

The Lord is addressed here as air because the air is the most important representation of all the demigods, being all-pervasive. Arjuna also addresses Kṛṣṇa as the grandfather because He is the father of Brahmā, the first living creature in the universe.