Bhagavad Gita 15.11
Yogis with purified minds see the Self within, while the unrefined miss it despite effort.
यतन्तो योगिनश्चैनं पश्यन्त्यात्मन्यवस्थितम्।
यतन्तोऽप्यकृतात्मानो नैनं पश्यन्त्यचेतसः॥
yatanto yogināścainaṃ paśyantyātmanyavasthitam
yatanto'pyakṛtātmāno nainaṃ paśyantyacetasaḥ
Translation
Striving yogis see this Self established within themselves. But those whose minds are unrefined and unthinking do not see it, however hard they strive.
Hindi
प्रयत्न करने वाले योगी इसे अपने भीतर स्थित देखते हैं। पर जिनका अंतःकरण शुद्ध नहीं हुआ और जिनमें विवेक नहीं है, वे प्रयत्न करके भी इसे नहीं देख पाते।
Commentary
Effort alone is not enough, and the verse is honest about it. A yogi sees the Self within because the mind has been purified, while an unprepared mind keeps missing it even when it tries. This is why the Gita keeps joining practice with discipline of character. 15.12 turns from the seer to the light the Lord shines in the world.