Lord Visnu said, “I Myself have manifested in the Form of Bhagavad-gita. Please understand that the first five chapters are My five heads, the next ten chapters are My ten Arms, and the Sixteenth Chapter is My stomach. The last two chapters are My lotus-feet. In this way you should understand the transcendental Deity of the Bhagavad-gita.
Source: Gita Mahatmya – Folio Vedabase