Bhagavad Gita Chapter 6, Verse 26

यतो यतो निश्चरति मनश्चञ्चलमस्थिरम् | ततस्ततो नियम्यैतदात्मन्येव वशं नयेत् ||

yato yato niścarati manaś cañcalam asthiram tatas tato niyamyaitad ātmany eva vaśaṁ nayet

Wherever the restless and unsteady mind wanders, one should restrain it and bring it back under the control of the Self.

Krishna addresses the common challenge of the wandering mind. 'Yato yato niścarati manaś cañcalam asthiram'—from wherever (yataḥ yataḥ) the restless (cañcalam) and unsteady (asthiram) mind (manaḥ) wanders (niścarati). This means: the mind is naturally restless and unsteady—it wanders to many places, jumps from thought to thought, doesn't stay still. This is normal. 'Tatas tato niyamyaitad ātmany eva vaśaṁ nayet'—from there (tataḥ tataḥ), having restrained (niyamya) this (etat), one should bring (nayet) it under control (vaśam) in the Self (ātmani) alone (eva). This means: whenever your mind wanders, wherever it goes, restrain it and bring it back to the Self. Don't fight it, don't get frustrated—just gently bring it back. This is the practice: mind wanders, you notice, you restrain it, you bring it back to Self. Over and over, until the mind learns to stay in the Self.