1.37. Or the mind taking as an object of concentration those who are freed of compulsion.
Meditation is a odd thing in Yoga. On one hand, we try to let things go as much as possible, but on the other, we try to develop effortless concentration. As things come into the mind, training it to either latch on to it or let it go takes a long time.
There are many "objects of meditation". In Kriya Yoga, the object of meditation is the spot at the base of the nose, called the third eye, or the Ajna Chakra. If you have ever wondered why Hindu's have the dot on their forehead, it's to represent this location.
At some point though, many objects of meditation become religious symbolism and lose their meaning altogether. This sutra refers to "ones that are freed of compulsion". This is a direct reference to holy men and women, considered to be pure. Just as Catholics worship the Virgin Mary or Jesus, Hindus have many objects of worship in the form of deities. Krisha, for example, is considered a pure embodiment of the preserver god Vishnu.
How does this work? When one focuses on the object of meditation, the essence of that object is meant to be absorbed by the mind, thereby blocking out other distractions. Let's say I decide to Meditate on Favor Flav. On the surface, Mr. Flav bounces around the stage for Public Enemy, going Yeeah Boi! Chuck D admitted they keep him around because he is the worlds best hype man. Now if you have seen him on the many reality shows that he has been on, there is a deeper quality to Mr. Flav. He is a very intelligent and deep thinker. A philosopher of the street.
Don't pick him as a object of meditation, but a hope you get the point. I like to use mantra chanting myself because I can focus on the vibrational quality of the syllables. The calming and joyful sensation is the feeling behind the mantra itself, which is then meditated upon.