In plain words
When a very high temperature forms in the body and then goes down, water arises. When we travel in the sun, the whole body breaks into sweat. Water arises from heat. The solidifying of water is Prakṛti. That is to say, water itself turns into solid matter. This takes shape as the vast Prakṛti. An example. We placed a jasmine flower on a table in a room. Its fragrance spread through the whole room. The space the jasmine took up is very small. But the space the fragrance took up is very large. The jasmine is solid. The fragrance is subtle. In the same way, water takes up more space than vapour and moisture. Sunlight takes up more space than water.
Man's intelligence, his mind, his nature: when it takes on a subtle form, it knows vastness. Through the senses it is drawn by the many vāsanās of the sense objects and by things. The more its ties with things grow, the more the mind's breadth keeps dwindling. Only when we reduce our desires does the mind gain breadth. What is the reason man is tied down in the world, bound, and lives in unrest? The cause of unrest is just this: gathering too much of what is mixed up with sense objects. Neither the world nor saṃsāra has hands and feet with which to bind. Through Prakṛti you bind yourself; Prakṛti does not bind you. You yourself cling to Prakṛti and are bound by your attachment and possessiveness towards it. To hold ourselves back from the sights of Prakṛti, we must keep sight, hearing and the tongue under control.
For the gross, the subtle and the causal, we may take the tamarind as an example. Outside, the shell; inside, the fruit. Within that, the stone: the seed. The body is like the shell on the tamarind. The mind is like the fruit within. The causal body is like the seed in it. The combined form of these three is humanness. In it are the annamaya, prāṇamaya, manomaya, vijñānamaya and ānandamaya kośas. Three qualities belong to the annamaya kośa. Hunger, thirst, sleep. These three belong to the nature of the body. The prāṇamaya kośa has three qualities. The power of breathing in, the power of breathing out, and the power of movement. The manomaya kośa too has three qualities. They are saṅkalpa, vikalpa and manana. In the same way, the powers of medhā, Viveka and Vijñāna are the three qualities of the vijñānamaya kośa. Then the ānandamaya kośa. It begins from priya. Priya, moda and pramoda: these are the three elements of the ānandamaya kośa.
Every person longs for these three: priya, moda and pramoda. The joy that arises on seeing the one we like is the joy of priya. The experience of a thing we like is moda. To come to feel one with a person, things and matters we like is pramoda. A man heard that mangoes, which he liked, had come into the market. As soon as he went and saw them, joy arose.