45.समाधि सिद्धिःीश्वरप्रणिधानात् ॥४५॥

samādhi siddhiḥ-īśvarapraṇidhānāt ||45||

By sacrificing all to Isvara comes Samadhi.

By resignation to the Lord, Samadhi becomes perfect.

46.स्थिरसुखमासनम् ॥४६॥

sthira-sukham-āsanam ||46||

Posture is that which is firm and pleasant.

Now comes Asana, posture. Until you can get a firm seat you cannot practice the breathing and other exercises. The seat being firm means that you do not feel the body at all; then alone it has become firm. But, in the ordinary way, you will find that as soon as you sit for a few minutes all sorts of disturbances come into the body; but when you have got beyond the idea of a concrete body you will lose all sense of the body. You will feel neither pleasure nor pain. And when you take your body up again it will feel so rested; it is the only perfect rest that you can give to the body. When you have succeeded in conquering the body and keeping it firm, your practice will remain firm, but while you are disturbed by the body your nerves become disturbed, and you cannot concentrate the mind. We can make the seat firm by thinking of the infinite. We cannot think of the Absolute Infinite, but we can think of the infinite sky.

47. प्रयत्नशैथिल्यानन्तसमापत्तिभ्याम् ॥४७॥

prayatna-śaithilya-ananta-samāpatti-bhyām ||47||

By slight effort and meditating on the unlimited (posture becomes firm and pleasant).

Light and darkness, pleasure and pain, will not then disturb you.

48. ततो द्वङ्द्वानभिघातः ॥४८॥

tato dvaṅdva-an-abhighātaḥ ||48||

Seat being conquered, the dualities do not obstruct.

The dualities are good and bad, heat and cold, and all the pairs of opposites.

49. तस्मिन् सति श्वासप्रश्वास्योर्गतिविच्छेदः प्राणायामः ॥४९॥

tasmin sati śvāsa-praśvāsyor-gati-vicchedaḥ prāṇāyāmaḥ ||49||

Controlling the motion of the exhalation and the inhalation follows after this.

When the posture has been conquered, then this motion is to be broken and controlled, and thus we come to Pranayama; the controlling of the vital forces of the body. Prana is not breath, though it is usually so translated. It is the sum-total of the cosmic energy. It is the energy that is in each obdy, and its most apparent manifestation is the motion of the lungs. This motion is caused by Prana drawing in the breath, and is what we seek to control in Pranayama. We begin by controlling the breaht, as the easiest way of getting control of the Prana.