Bhagavad Gita 6.26

यतो यतो निश्चरति मनश्चञ्चलमस्थिरम्।ततस्ततो नियम्यैतदात्मन्येव वशं नयेत्॥

yato yato niścarati manaścañcalamasthiram |tatastato niyamyaitadātmanyeva vaśaṃ nayet ||

From whatever cause the restless and unsteady mind wanders away, let him restrain it from that and bring it under the control of the Self alone.

When the volatile and wavering mind wanders, let him restrain it and bring it back to its allegiance to the Self.

Our plain-language meaning of this verse is waiting for scholar review.