In plain words
Where do they come from? What is their root? It is the ocean. The ocean is one! The waves look different; the forms and names look different. Though the forms and names look different, whatever taste, whatever coolness, whatever wetness there is in the ocean, those very qualities are in these waves. Look into any wave: there is wetness, there is coolness, there is whiteness. In the ocean too the same are there. Put a drop of the ocean in your mouth and it is salty. Put a drop of water from a wave in your mouth, and that too is salty all the same. Now from these waves foam arose. What is the basis of the foam? The waves are its basis. What is the basis of the waves? The ocean is the basis. What is the basis of all three? That ocean itself is the basis. The very water that is in the ocean, rising as the waves, as the foam in the wave, takes on three forms. That is pratyakṣa, parokṣa and anumāna. Pratyakṣa, parokṣa and anumāna: all three have one root! That is Advaita. They called Divinity a tripuṭī. The oneness in which the three come together is itself the Ātmatattva.
The Ātma alone is the root of humanness!
Cit, acit and Īśvaratva are the parts of the three. Cit means the inert, acit means the physical, and Īśvaratva means what the three times cannot touch. The oneness of these three is the inner meaning of life. One is the body, the second is the Manas, the third is the Ātma. The body has taken the Manas as its basis. The Manas rests on the Ātma as its basis. For everything, the Ātma alone is the basis. The Ātma alone is the root of humanness. That is Advaita, he went on teaching. People who cannot recognise this truth enter into physical, worldly and material matters, endure many kinds of hardship, and at the very last realise the Ātmatattva. To Śuddhodana, after long years without one, a son was born. His name was Siddhārtha. Wanting to see that this son met no hardship, pain or sorrow in the material world, he would not send him outside, out of the house.