Verse 24

आत्मनो व्यतिरेकेण न किंचिदपि विद्यते ।सर्वं ब्रह्मेति मे तत्त्वमेतत्तद्भावयाम्यहम्

In plain words

Apart from the ātman, nothing whatsoever exists. 'All is Brahman' -- this is my tattva; that I hold in contemplation.