Mundaka 1.1.8 Trans & Comms

tapasā cīyate brahma tato‘nnamabhijāyate. annāt prāṇo manaḥ satyaṁ lokāḥ karmasu cāmṛtam. (1.1.8) 

tapasā – by knowledge; brahma – Brahman; cīyate – bulges; tataḥ – from that; annam – the unmanifest (jagat); abhijāyate – is born; annāt – from the unmanifest; prāṇaḥ – hiraṇyagarbha; manaḥ – total mind; satyam – five elements; lokāḥ – worlds; karmasu ca – and due to actions; amṛtam - the results (are born) 

Brahman bulges by knowledge. From that Brahman the unmanifest is born. From the unmanifest, hiraṇyagarbha is born. Then the total mind, the five elements, the worlds and actions are born. And due to actions, results are born.

Brahman itself does not undergo any change. Brahman therefore gets seemingly ‘connected’ to māyā. From the unmanifest, which is māyā, the jagat is going to manifest now, just as the sprout, which exists in the seed in a potential but unmanifest form, emerges from the seed.

~Dayananda

In brooding meditation or continuous thought (tapas), the total creative urge (Brahmā) swells (with the very joy of creation). From Him food is produced, from food the prāṇa, the mind, the bhūtas, the worlds and in the karmas their fruits (are produced).

The creative urge in Reality, in its own potency, swells in an impatience of self-expression, and then from that the whole world of objects constituting the plane of matter emerges out. From matter, life as known to us manifests. Prāṇa, here means life; prāṇa is the centre of all activities.

~Chinmayananda

Brahman expands by means of austerity, and from It primal matter is produced; from matter, Prana; from Prana, mind; from mind, the elements; from the elements, the worlds; thence works, and from the works, their immortal fruits.

The word tapas in the text means, literally, austerity. It also denotes intense thinking, which precedes any creative act. Here the word means knowledge regarding the future creation. Brahman, or Pure Intelligence, alone exists; It is one and without a second. Under the influence of Its own maya there arises in Brahman the desire for creation, or projection, and forthwith It becomes endowed with omniscience, that is to say, with the knowledge and capacity of creating, preserving, and destroying the universe. Thus Brahman appears to increase in size, like a seed before it splits and the sprout comes out. In this stage Brahman, or the attributeless Absolute, becomes known as Saguna Brahman, or Brahman associated with the attributes of omniscience, omnipotence, and so on. The whole creation is the illusory superimposition of name and form on Brahman, owing to maya. Maya has no existence independent of Brahman.

~Nikhilananda