In plain words
So the inner meaning of yogakṣema is: to earn the divinity that is beyond the human, and to guard the divinity so earned. We may call this divinity, joined with yoga and kṣema, enjoyment joined with sacrifice. So yoga joined with sacrifice is most necessary for humanness. When we take up such sacrifice, an individuality that is divinity itself arises within our very humanness. So man must not make light of the sayings of the Upaniṣads, but with a divine feeling gather them within himself and make the effort fit to keep them in his daily practice.
Man is not made up only of the principles of body, mind and spirit. In him there is also a power of prajñā that is beyond these. This is what they called prajñā. Every human being must keep this power of prajñā in view. It pervades all, in the mind, in the body, in the antaḥkaraṇa, in everything. What is the antaḥkaraṇa? It is right here that yoga joined with sacrifice comes to us. The antaḥkaraṇa is this: the form in which these four, Manas, Buddhi, citta and Ahaṅkāra, are blended is called the antaḥkaraṇa. Here, what is Manas? Manas is ceaseless thinking. They said, Saṅkalpavikalpakātmakaṃ manaḥ. It is made of saṅkalpa and vikalpa. It is a cloth. In this cloth, threads called warp and weft, that is, the upright and the across, are joined together. That is what is made of saṅkalpa and vikalpa. If we go on pulling out the threads on one side, there is no cloth. In the same way, if we go on pulling out these threads called saṅkalpas, the very form called Manas will not be. This is what they called manana trāṇa sammiḷitam. It is by these saṅkalpas alone that we are developing the power of manana and trāṇa. This Manas is a form made of saṅkalpas. Citta means thinking itself. That we think on the tattva. Buddhi is the power that decides. It is the divine intelligence that weighs what is eternal and what is passing. And the fourth is Ahaṅkāra. Ahaṅkāra is to take the form alone as the basis and feel, "I"; to think, "the form is I", is itself Ahaṅkāra. Aham + ākāra: this is Ahaṅkāra. Manas, Buddhi, citta, Ahaṅkāra of the senses: these four are only changed forms of Manas.