Bhagavad Gita · 12.2

श्रीभगवानुवाचमय्यावेश्य मनो ये मां नित्ययुक्ता उपासते।श्रद्धया परयोपेतास्ते मे युक्ततमा मताः॥

śhrī bhagavān uvācha mayy āveśhya mano ye māṁ nitya-yuktā upāsate śhraddhayā parayopetās te me yuktatamā matāḥ

The Supreme Lord said: Those who fix their minds on me, who worship me with steadfast devotion and supreme faith — I consider them to be the most perfect in yoga.

— Bhagavad Gita 12.2

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)