BRAHMAM-THE SUPREME CAUSE OF ALL:-

Chapter:-2.

Section:-1.

Slokam:-3.

Etasmaj-jayate  prano  manah  sarvendriyani  ca,

kham  vayur-jyotir-apah  prthivi  visvasya  dharini.

From Him are born the Prana ( life ), the mind, all the organs, the sky ( Akasa), the wind (Vayu), the fire ( Jyotih ), thewater ( Apah), and the earth( Prthivi) which supports all.

From the Supreme Reality explained in the previous mantra, was created the entire world, knowable and knowing objects. Thus here, we have the enumeration explaining that the five elements, the ten senses, the Prana and the mind came out of Brahmam( The Supreme). It is Sastrik declaration that the form--quality of creation has come out of seventeen tattvas. Also, it declares that the entire world of activity (prana), of feelings(mind), of cognition ( sense organs), and the outer world of the five great elements have all the same source in the eternal Realty as explained in the previous mantra, In case, the pyre Existence viz. the Reality is removed from the created world, we shall find the observed world of plurality dwindling itself into nothingness or non-existence.

Explanation:-

In vedanta, this idea is explained by means of an analogy of a piece of cloth in which some patterns and forms are woven in by the same thread as that of the cloth. So long as the cloth is observed as such, the names and forms represented in it are true and real. But when we draw out the thread we find  that all the names and forms merge themselves to form a bundle of threads; and if the threads are unwound, nothing remains but a quantity of cotton. In the final analysis, the names and forms on the piece of cloth, including the very cloth-piece, were nothing but a seeming transformation of the cotton-stuff.Removing all the cotton, neither the cloth nor the pattern can remain. In cotton it exists, out of cotton it has come and into cotton alone can it merge back. 

Similarly  the pure Consciousness, the Eternal Pure Wisdom is That Knowledge, 'knowing which every other knowledge becomes known' ; out of this Absolute Knowledge has all the world of names and forms emerged out, and in it they exist and into it they merge back. It is, in order to make us understand this single idea in all its pregnant imports, that the mother Sruti has started this section with ever so many mantras, each in different ways, expressing this one and the same idea.