In plain words
The principle of the Ātma in all is one
Parameśvara too created one such liṅga, the emblem of the nature of Īśvara, gave it to Mārkaṇḍeya's parents, and taught them to contemplate this divinity. Worshipping that very form of the liṅga, they made their lives fruitful. The principle of the Ātma does not waver. The principle of the Ātma in all is one and the same. In those days Mārkaṇḍeya and his father Mṛkaṇḍu understood this sacred principle well, and went on worshipping divinity in this way, in the form of the liṅga. In the body of every being there are three parts. The gross, subtle and causal bodies. The outer form is the gross one. The one principle of the Ātma dwells within these gross, subtle and causal bodies as the inner controller. This is the thread. Without this thread there is no handkerchief. Without silver there is no plate. Without clay there is no pot. Without Brahman there is no world. This Brahman is like the thread. The gross, subtle and causal bodies, all three, are in the Creator Himself. But merely being there in that way does not make a cloth. The warp and the weft must be joined from both sides. This is precisely human effort and God's grace. Only when these two come together does the fruit come to hand. The words we speak and the deeds we do are the very things that arise in our subtle body and turn outward!
The Veda is the form of God
Today all the students are reciting the Veda. Each one of these Vedic mantras belongs to a particular form of divinity! If man is to recognise his true nature, the Veda itself is the authority for it. Those who recite what they have learnt just as they learnt it, they alone become worthy of true realisation. As for how the vision of God comes about: only when it comes from the heart does the form emerge clearly. That itself is the direct proof! That itself is the indirect proof too! That alone is the basis of every sādhana. When the children chant the Vedic mantras here, the women over there chant those mantras well too.