1. WHAT IS SAMYAMA
The three (Dharana, Dhyana and Samadhi) together constitute Samyama.
Samyama means perfect control of the mind. Here it is a technical name for three inseparable processes of Dharana, Dhyana and Samadhi taken collectively. By the practice of Samyama, the Yogi gets knowledge and powers. The three processes are practised on any one object successively at the same time. The five Angas of Yoga are intended to purify the body, Prana and the senses. These three practices purify the mind. They constitute the very basis of Yoga. With the help of these three, the Yogi dives deep within and brings out the pearl of knowledge of anything. Samyama is the name given to the combined practice of Dharana, Dhyana and Samadhi at one and the same time. By Samyama on external objects he gets various Siddhis and hidden knowledge of the universe of Tanmatras, etc. By concentration on Indriyas, Ahamkara and mind, etc., he gets various powers and experiences. These things are explained in the subsequent Sutras.
2. SAMYAMA AS ANTARANGA SADHANA
The three (Dharana, Dhyana and Samadhi) are more internal than the preceding (Yama, Niyama, Asana, Pranayama and Pratyahara).
These three constitute the Yoga proper. The five accessories are the external means of Yoga. These three directly bring Samadhi. The other five purify the body, Prana and Indriyas. Hence these three are called Antaranga Sadhana.
3. SAMYAMA AS BAHIRANGA SADHANA
Even that (Samyama) is external to the seedless Samadhi.
Nirbija Samahi or Asamprajnata Samadhi is the final goal of Raja Yoga. Compared to that, this Samyama (Dharana, Dhyana, Samadhi) also is external or indirect. It is also preparatory. Here there is Alambana or something for the mind to depend upon; whereas in Nirbija Samadhi, there is nothing for the mind to depend upon. It is Niralambana. It is Nirbija (seedless) Samadhi.
4. BENEFITS OF SAMYAMA
By the conquest of Samyama, comes the stage of cognition.
As Samyama becomes firmer and firmer, so does the knowledge of Samadhi become more and more lucid. This is the fruit of the practice of Samyama. Samyama should become very natural. Then the knowledge flashes like anything. Samyama is a powerful weapon for the Yogi. Just as the archer aims at the gross objects at first, and then takes to subtle objects, so also the Yogi does Samyama on gross objects and then takes to subtle objects. He does great deal of practice and ascends the Yogic ladder rung by rung.