Bhagavad Gita 15.11
यतन्तो योगिनश्चैनं पश्यन्त्यात्मन्यवस्थितम्। यतन्तोऽप्यकृतात्मानो नैनं पश्यन्त्यचेतसः।।15.11।।
yatanto yoginaścainaṃ paśyantyātmanyavasthitam| yatanto'pyakṛtātmāno nainaṃ paśyantyacetasaḥ||15.11||
yatanto yoginashcainam pashyantyatmanyavasthitam yatanto'pyakritatmano nainam pashyantyacetasah15.11
Meaning
Striving yogis can perceive the Self established in their own being. But the unrefined, whose minds are not purified, cannot perceive the Self even though they try.
योगीजन प्रयत्न करते हुए ही अपने हृदय में स्थित आत्मा को देखते हैं, जब कि अशुद्ध अन्तःकरण वाले (अकृतात्मानः) और अविवेकी (अचेतसः) लोग यत्न करते हुए भी इसे नहीं देखते हैं।
This is verse 11 of 20 in Chapter 15 (Purushottama Yoga) of the Bhagavad Gita.