Bhagavad Gita 15.11

यतन्तो योगिनश्चैनं पश्यन्त्यात्मन्यवस्थितम् |
यतन्तोऽप्यकृतात्मानो नैनं पश्यन्त्यचेतस:

Translation

Striving yogis too are able to realize the soul enshrined in the body. However, those whose minds are not purified cannot cognize it, even though they strive to do so.