In this sutra we have two important words; one is yoga and another is anushasanam.
There are many activities in the mind. Yoga is a restraint of these activities. Yoga is a practice that brings various changes in the state of citta, the conscious mind.
Yoga is one of the six darshanas, which is being practised by the citizens of Bharathavarsha, since the ages.
Jnana the knowledge is too much. Bhavana the feelings are too many. Kriya the actions are endless.
This trance or Samadhi happens when you control the thought waves of your mind. There is a stillness of the mind in samadhi. You have to know the mind and its state and contemplate to bring the stillness of the mind.
These three qualities are natural and also are known as the evolutes of nature. Everyone has these three qualities.