Chapter 6 · The Yoga of Meditation · Krishna said
Bhagavad Gita 6.26 — Bringing the mind back
यतो यतो निश्चरति मनश्चञ्चलमस्थिरम्। ततस्ततो नियम्यैतदात्मन्येव वशं नयेत् ॥
yato yato niścarati manaścañcalamasthiram | tatastato niyamyaitadātmanyeva vaśaṃ nayet ||
Meaning
Wherever the restless, unsteady mind wanders, he should draw it back from there and bring it again under the control of the Self.