In the last few verses, there were detailed instructions on how to meditate and even what precautions to follow in terms of food, actions and sleep. Now, how can a person know, if his meditation is progressing well? This is answered in the next Sloka

यदा विनियतं चित्तमात्मन्येवावतिष्ठते ।
निःस्पृहः सर्वकामेभ्यो युक्त इत्युच्यते तदा ॥६- १८॥

yadaa viniyatam chittamaatmanyevaavatishhThate .
niHspR^ihaH sarvakaamebhyo yukta ityuchyate tadaa .. 6.18..

When a person’s thoroughly disciplined mind gets focused on God alone, then this person who is free from yearning for all enjoyments, is said to be established in yoga

viniyataM chittaM – thoroughly disciplined mind : yadaa – when : aatmani eva – exclusively on God : avatishhThate – gets focussed : tadaa – then : niHspR^ihaH – free from yearning : sarva kaamebhyaH – for all enjoyments : yuktaH iti uchyate – is spoken of as established in yoga

When a person becomes firm in meditation, then his mind stops running after those thoughts which are caused by desires. When a person is meditating and trying to think about the Lord, but suddenly thinks of eating an ice cream, or buying a car or house or thinks about the promotion he might get etc., then it means that all the yearnings for the enjoyments of the world are still there. He still has desire for the worldly objects and has not become focused in his goal of God realization.

The desire for worldly objects is so strong that even people who appear to be great devotees sometimes cannot free themselves from it. Three priests were discussing about what they do with the money that they get in the collection plate. One priest said, “I draw a line and then throw the money in the air. Whatever lands in front of the line, I give it to God and I take the rest.” The second priest said, “I also do something similar. I draw a circle and throw the money in the air. Whatever lands outside, I give to God and I keep the rest”. The third priest said, “I also do something similar. I throw all the money in air. Whatever God can catch, he can keep”

As long as a person has desire for worldly objects, there is no way that he can focus his mind on God. On the other hand, when a person is able to constantly think about the Lord alone, and no other thoughts disturb him, then it means he has become firmly established in meditation. This means that he has understood the true nature of the material objects and no more needs or wants them He is able to focus his entire attention on thinking about God and he is a true yogi.