BG 6.26
यतो यतो निश्चरति मनश्चञ्चलमस्थिरम्। ततस्ततो नियम्यैतदात्मन्येव वशं नयेत्
yato yato niśhcharati manaśh chañchalam asthiram tatas tato niyamyaitad ātmanyeva vaśhaṁ nayet
When the volatile and wavering mind wanders, let him restrain it and bring it back to its allegiance to the Self.
Translated by Shri Purohit Swami
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.
Translated by Swami Sivananda
Word meanings (from the gita/gita dataset)
yataḥ yataḥ—whenever and wherever; niśhcharati—wanders; manaḥ—the mind; chañchalam—restless; asthiram—unsteady; tataḥ tataḥ—from there; niyamya—having restrained; etat—this; ātmani—on God; eva—certainly; vaśham—control; nayet—should bring