In plain words
Yet the Veda spells out this sacred body of words in separate words and gives out the drops of sound. Thinking that in the land of Prakṛti the tranquil principle itself is God, the words they uttered, longing to become worthy of that God's grace, became the Ṛks. Then the hope and longing of the individual was to understand the supreme principle through rites such as yajña and yāga, and to attain divinity. For that they went on taking up yajñas and yāgas. Such ritual work itself was named the Yajur Veda. Moreover, because it wished to bestow song that was sacred, true to pitch, sweet, delicate and of noble character, and so gave the song of Ānanda, it came by the fitting name of Sāma Veda. So that there would be no reproach that the scholars had forgotten the everyday world, and in order to develop the principle of humanness that holds both the path of śreyas and the path of preyas, the scholars took the Atharvaṇa Veda as their basis. But believing that the Atharvaṇa Veda was not apauruṣeya, they regarded only the Ṛg Veda, the Yajur Veda and the Sāma Veda as the chief ones and went on calling this ‘Trayī’. But in order to make one recognise the true principle that is the root of every Dharma, the key to every śāstra and the goal of every sādhana, this Atharvaṇa Veda became in many ways a model for the physical paths. Though each Veda followed only one method, this Atharvaṇa Veda set out to follow all the other Vedas together. Teaching that the Ṛg Veda is speech, the Yajur Veda the Manas and the Sāma Veda the life-breath, the Atharvaṇa Veda went on gathering up the essence of these three Vedas and giving it out in full. Speech may well be the Ṛg Veda, but it explained what kind of speech is the Ṛg Veda. The Manas is the Yajur Veda, but it also taught what kind of Manas comes into harmony with the Yajur Veda.