Bhagavad Gita, Chapter 7, Verse 24

The foolish regard Me, the unmanifested, as come into manifestation, not knowing My supreme state, immutable and transcendental.

A real, personal form isn't described here as something added on later, it's part of what's always been true.

This corrects a real, common misunderstanding directly. The visible form isn't framed as a recent addition to something originally formless, it's described as genuinely eternal in its own right, not a lesser, temporary version of something else.