Or achievement of supernormal perception of a divine object brings the mind to steadiness
When one makes a concentration (dhāraṇā) on the tip of the nose, he will have a sensation (saṃvit) of divine fragrance; on the palate, of colour; on the middle of the tongue, of touch; and on the root of the tongue, of sound. These supernormal perceptions arising hold the mind in steadiness, remove doubts, and become a means to samādhi cognition (samādhi-prajñā).
In the same way experiences like the moon, sun, a planet, a jewel, a light or a ray, are to be known as supernormal perceptions of actual objects.
Although what is understood from the scriptures and inferences from them, and from instruction by a teacher, are real facts, since these are qualified to describe things as they really are, still until some one part of it has been known directly for oneself, it is all second-hand as it were, and does not produce a firm conviction about release and other subtle things. Therefore some one definite thing has to be directly experienced in confirmation of what has been learned from scripture and inference and the teacher.
Or a supernormal perception of a divine object brings the mind to steadiness. This is a yogic perception, of some object like fragrance, for example, when that has been made the object of the meditation. There is a direct awareness (saṃvedana) of that fragrance.
For the yogin who is practising yoga which is to give face-to-face experience, the perception is the first direct awareness, and it gives him confidence, creating enthusiasm for the practice of yoga; it is like the appearance of smoke when wood is being rubbed together to create fire. Such a perception fills him with joy because of the confidence it creates, and brings his mind to steadiness.
When one makes a concentration on the tip of the nose, he will have a sensation (saṃvit) of fragrance an experience of delightful fragrance arises and continues, as if by the ordinary sense contact. This is the perception of fragrance. So with the tongue and others; they are the locations of concentration. These perceptions hold the mind in steadiness, remove doubts, and become a means to samādhi-cognition.
The forms of a ray, moon, sun, planet, or a light and so on, appearing to one who is concentrating his mind on them, or spontaneously when the meditation on the lotus of the heart is unsteady (vaiṣamya), are to be known as perceptions of actual objects.
Although what is understood from the scriptures and inferences from them and from instruction by a teacher, are real facts, and there is no uncertainty about them, inasmuch as there is no contradictory teaching, still until some one part of it has been known directly for oneself until there is a direct perception (pratyakṣa) of at least one thing taught by them it is all second-hand, as it were, and does not produce a firm conviction about such subtle things as release. Therefore some specific thing has to be directly experienced, to reinforce what has been so learnt.
When some one thing out of what has been taught has been directly perceived, everything else is firmly believed’, including such subtle matters as release, and this is why the yogin is directed to train the mind in this way.
As regards the concentrations of the mind which have not been mastered, when the consciousness of mastery has arisen in regard to the objects (so far practised), he will be able to perceive directly (and thereby master) all the others. Then faith, energy, memory and samādhi will come to him without hindrance.
When some one thing out of what has been taught has been directly perceived, everything else is firmly believed, including such subtle matters as release, and this is why the yogin is directed to train the mind in this way, beginning with friendliness and compassion (sūtra I.33) up to mastery, from the ultimate atomic particles up to ultimate magnitude (sūtra I.40); the training is set out in the section beginning with restraints, observances, posture and so on (sūtra II.29).
To sum up: by undertaking one of the practices taught in this section, some one thing is directly perceived; by this, doubt is removed and faith firmly established in the teachings right up to such subtle things as release, the extravertive mental processes are calmed, and the detachment called consciousness of mastery is accomplished. Then he will be capable of experiencing directly any of the things taught in the third chapter, beginning with the three transformations (past, present and future), whether to attain knowledge or powers. This is the purpose of teaching this mental training here, as the commentator has explained.