yato yato nishcharati manashchanchalamasthiram |
tatastato niyamyaitadaatmanyeva vasham nayet || 26 ||

Wherever the fickle and unstable mind strays, remove it from there and constantly focus it only on the self.
yataha : wherever
nishcharati : strays
manaha : mind
chanchalam : fickle
asthiram : unstable
tataha : from there
niyamya : remove
etat : it
aatmani : self
eva : only
vasham : focus
nayet : constantly
Having asked the meditator to slowly but surely practice meditation, Shri Krishna elaborates on what exactly is the aspect of meditation that needs constant practice and repetition. He urges the meditator to check the mind as soon as it strays into another thought, and bring it back to the thought of the self. The meditator has to do this again and again, each time the mind strays. It is one of the most practical shlokas about meditation.
As we practice meditation, we begin to appreciate the speed at which the mind moves from thought to thought. For example, let’s say that the thought of taking a one week vacation enters the mind. It then leads to a chain of thoughts. First the mind makes a list of all our favourite vacations spots. Then it calculates how much each place will cost. Then it visualizes what each of those places looks like. It might also bring up memories of past vacations. The mind has thought all of this within seconds. By the time we are aware that the mind is thinking like this, it has strayed far away from the object of meditation.
So therefore, Shri Krishna urges us to be extremely vigilant and alert with regards to our thoughts during meditation. We have to cultivate this vigilance as a habit. We have vigilant habits in other parts of our life. Men, for example, check their face daily for any stray hairs just after shaving. Similarly, we should be vigilant about stray thoughts during meditation. The constant practice of removing stray thoughts is called “abhyaasa”.
The mind loves to stray towards thoughts about objects, people and situations that we have given importance to. Abhyaasa helps us diminish our importance towards stray thoughts. Shri Shankaraachaarya in his commentary gives us a wonderful tip with regards to abhyaasa. Each time we encounter a stray thought, we should instantly analyze it like a scientist. We should inspect each thought and say: it is nothing but name and form on top of the eternal essence. If the thought is about name and form only, then it is not real, it is does not have “satyatva”. And if it is not real, it is not important, so I should not go after it.
Furthermore, if the very same thought occurs the next time, we should inspect it and say : I have already determined that this thought is not important to me. If we do so each time that same thought comes, we develop dispassion or vairagya towards it. Only then will meditation work properly.
If we follow this technique, the mind will eventually become quiet – “prashaanta”.