Who exists in becoming and non-becoming, that one does not exist in becoming and non-becoming; who exists in un-becoming and non-becoming, that one does not exist in un-becoming and non-becoming.

Dialectical play on bhava (becoming) and vibhava (un-becoming, annihilation). The sage does not exist in either extreme.

The Buddha rejects both eternalism (bhava — eternal becoming) and nihilism (vibhava — annihilation). The middle path is beyond both.