तत्रैकाग्रं मनः कृत्वा यतचित्तेन्द्रियक्रियः।उपविश्यासने युञ्ज्याद्योगमात्मविशुद्धये॥
tatraikāgraṃ manaḥ kṛtvā yata-cittendriya-kriyaḥupaviśyāsane yuñjyād yogam ātma-viśuddhaye
Word by word
The verse says
— there, making the mind one-pointed, with the workings of mind and senses held in, he should sit on that seat and practise, for his own clearing.
In plain words
The purpose is stated, and it is modest.
Ātma-viśuddhaye — for his own clearing.
Not for power. Not for visions. The same phrase used at 5.11 about ordinary work.
Where you've felt this · in study
You sit down at the same hour with your phone in another room. The first twenty minutes are useless every single time. They are also the reason the next forty are not.
Going deeper
The stated purpose is worth holding on to, because meditation attracts grander claims than this.
Ātma-viśuddhaye — for the clearing of the self. It is the same phrase Chapter 5 used about a person doing ordinary work with their hands, which means the sitting is not being placed in a separate category from sweeping.
That levelling is deliberate and it runs both ways. The work is not lesser than the meditation, and the meditation is not promising something the work cannot deliver.
Ekāgram — one-pointed. The literal sense is having one tip, like a spear. Attention with a single end rather than a spread.
And what makes the instruction usable is that it is stated as something to do, not something to achieve. You make the mind one-pointed. It does not say the mind stays that way, and the next several verses assume it will not.