B.G 6.26

यतो यतो निश्चरति मनश्चञ्चलमस्थिरम्। ततस्ततो नियम्यैतदात्मन्येव वशं नयेत् ॥२६॥

yato yato niścarati manaścañcalamasthiram। tatastato niyamyaitadātmanyeva vaśaṁ nayet ॥26॥

[यतो यतो निश्चरति मनः चञ्चलम् अस्थिरम्। ततस्ततो नियम्य एतत् आत्मनि एव वशं नयेत्॥
यतः (yataḥ) - wherever; यतः (yataḥ) - wherever; निश्चरति (niścarati) - wanders; मनः (manaḥ) - mind; चञ्चलम् (cañcalam) - fickle, restless; अस्थिरम् (asthiram) - unsteady; ततः (tataḥ) - from there; ततः (tataḥ) - from there; नियम्य (niyamya) - restraining, controlling; एतत् (etat) - this; आत्मनि (ātmani) - in the self; एव (eva) - only; वशं (vaśam) - control; नयेत् (nayet) - should lead, should bring; ]

Wherever, wherever the restless and unsteady mind wanders, from there and there, restraining it, one should bring it back on to the topic of 'ātman', the Lord, only.

Gīta Bhāshya 6.26

'yato yato' - wherever, wherever. 'ātmanyeva vaśaṁ nayet' - one should control and have it on the subject of 'ātman', the lord, alone.

यतो यतो यत्र यत्र । "यतो यतो धावति" इत्यादिप्रयोगात्। आत्मन्येव वशं नयेत् आत्मविषये एव वशीकुर्यात् इत्यर्थः ॥२६॥

yato yato yatra yatra । "yato yato dhāvati" ityādiprayogāt। ātmanyeva vaśaṁ nayet ātmaviṣaye eva vaśīkuryāt ityarthaḥ ॥26॥

[यतो यतो (yato yato ) - the expression 'yato yato' means; यत्र यत्र (yatra yatra) - wherever, wherever; "यतो (yataḥ) - wherever; यतो (yataḥ) - wherever; धावति (dhāvati)" - runs, moves; इत्यादि (ityādi) - similar; प्रयोगात् (prayogāt) - usage; आत्मनि एव वशं नयेत् (ātmani eva vaśam nayet) - The expresion 'ātmani eva vaśam nayet'; आत्मविषये (ātma-viṣaye) - in the subject of 'atma', the Lord; एव (eva) - alone; वशीकुर्यात् (vaśīkuriyāt) - should control; इति (iti) - thus; अर्थः (arthaḥ) - is the meaning; ]

The expression 'yato yato' means "wherever, wherever", similar to the usage 'wherever he runs'. 'ātmanyeva vaśaṁ nayet' means one should control and have it on the subject of 'ātman', the lord, only.