6.7, Sloka 7: Chapter 6:
A recipe for peace is given here. Lord Krishna says that that person is peaceful who has won over the senses and is absorbed in the supreme consciousness. Such a person is free from dualities. He treats heat, cold, happiness and sadness as the same. Also praise by people and also insults from people are the same for him. The key word in this sloka is being free from dualities. It means being in the same state (internally) to whatever happens externally. Irrespective of happenings in the outside world to a person, the person feels and responds in the same manner. This is the highest state of existence of a person. Usually, we get swayed by praise from our peers and we look forward to activities which draw a lot of praise from people. We also get demotivated by insults/lack of praise from people. If our actions are based on what we want from people in society then we are giving power to the external factor in a situation.
If the power is within us then we react same to whatever happens in our external surroundings. The internal state of the person should not change. Krishna uses the example of heat and cold as two opposite physical forms and how we react to them. He uses the feelings of happiness and sadness to explain the point. Can we feel the same emotion in all situations? This is highly difficult not an impossible situation. This is possible for a person who won over his senses and is absorbed in supreme consciousness.
6.8, Sloka 8: Chapter 6:
Lord Krishna gives the explanation of the meaning of Yogi. The words of gnana for Knowledge and vignana- wisdom are used in the first line. This indicates that a person having the correct knowledge regarding the ultimate truth and who uses this knowledge on himself and gains wisdom (Vignana) ,and who is fully satisfied with whatever he is having and whatever he is doing , and one who is undisturbed to whatever is happening externally (being equanimous) and who had conquered his senses and is absorbed with the supreme consciousness is said to be an yogi. An yogi with all the above-mentioned qualities will look at dirt, stone or gold as the same.