Bhagavad Gita
6.26

यतो यतो निश्चरति मनश्चञ्चलमस्थिरम् । ततस्ततो नियम्यैतदात्मन्येव वशं नयेत् ॥

yato yato niścarati manaścañcalamasthiram | tatastato niyamyaitadātmanyeva vaśaṃ nayet ||

Translation

Wherever the wavering and unsteady mind wanders, from there, restraining it, one should bring it back under the control of the Self alone.

Interpretation

The most honest and compassionate instruction in all of meditation literature. The mind is chancala (wavering) and asthira (unsteady) — this is its nature. It will wander. The instruction is not to prevent wandering through tension but to notice wandering and gently bring it back (niyamya etad) to the Self. Yato yato (wherever it goes) — tatastato (from there, from wherever) — bring it back. This is the entire practice of meditation, repeated as many times as necessary, without frustration or self-criticism.