Bhagavad Gita 2.41 Chapter 2, Verse 41

व्यवसायात्मिका बुद्धिरेकेह कुरुनन्दन ।
बहुशाखा ह्यनन्ताश्च बुद्धयोऽव्यवसायिनाम् ॥२.४१॥

vyavasāyātmikā buddhirekeha kurunandana
bahuśākhā hyanantāśca buddhayo'vyavasāyinām

Meaning

O joy of the Kurus, those on this path have a single, resolute understanding, but the thoughts of the irresolute are many-branched and endless.

Newly written by Bhajan Dhun — scholarly review in progress.

Reference: Bhagavad Gita 2.41 (Chapter 2, The Yoga of Knowledge (Sankhya Yoga), Verse 41)