SB 7.9.35

sa tv ātma-yonir ativismita āśrito ’bjaṁ
 kālena tīvra-tapasā pariśuddha-bhāvaḥ
tvām ātmanīśa bhuvi gandham ivātisūkṣmaṁ
 bhūtendriyāśayamaye vitataṁ dadarśa
Synonyms: 
saḥ — he (Lord Brahmā); tu — but; ātma-yoniḥ — who is born without a mother (directly begotten by the father, Lord Viṣṇu); ati-vismitaḥ — very much surprised (not finding the source of his birth); āśritaḥ — situated on; abjam — the lotus; kālena — in due course of time; tīvra-tapasā — by severe austerities; pariśuddha-bhāvaḥ — being completely purified; tvām — You; ātmani — in his body and existence; īśa — O my Lord; bhuvi — within the earth; gandham — aroma; iva — like; ati-sūkṣmam — very subtle; bhūta-indriya — composed of elements and senses; āśaya-maye — and that filled with desires (the mind); vitatam — spread out; dadarśa — found.
Translation: 
Lord Brahmā, who is celebrated as ātma-yoni, having been born without a mother, was struck with wonder. Thus he took shelter of the lotus flower, and when he had been purified after undergoing severe austerities for many hundreds of years, he could see that the cause of all causes, the Supreme Personality of Godhead, was spread throughout his own body and senses, just as aroma, although very subtle, is perceived in the earth.
Purport: 

Here the statement of self-realization ahaṁ brahmāsmi, which is interpreted by the Māyāvāda philosophy to mean “I am the Supreme Lord,” is explained. The Supreme Lord is the original seed of everything (janmādy asya yataḥ; ahaṁ sarvasya prabhavo mattaḥ sarvaṁ pravartate). Thus the Supreme Lord extends everywhere, even throughout our bodies, because our bodies are made of material energy, which is the Lord’s separated energy. One should realize that since the Supreme Lord spreads throughout one’s body and since the individual soul is a part of the Supreme Lord, everything is Brahman (sarvaṁ khalv idaṁ brahma). This realization was achieved by Lord Brahmā after he was purified, and it is possible for everyone. When one is completely in knowledge of ahaṁ brahmāsmi, he thinks, “I am part of the Supreme Lord, my body is made of His material energy, and therefore I have no separate existence. Yet although the Supreme Lord is spread everywhere, He is different from me.” This is the philosophy of acintya-bhedābheda-tattva. An example given in this regard is that of the aroma within the earth. In the earth there are aromas and colors, but one cannot see them. Actually we find that when flowers grow from the earth, they appear with different colors and aromas, which they have certainly gathered from the earth, although in the earth we cannot see them. Similarly, the Supreme Lord, by His different energies, spreads throughout one’s body and soul, although we cannot see Him. An intelligent man, however, can see the Supreme Lord existing everywhere. Aṇḍāntara-stha-paramāṇu-cayāntara-stham: the Lord is within the universe and within the atom by His different energies. This is the real vision of the Supreme Lord for the intelligent man. Brahmā, the first created being, became the most intelligent person by his tapasya, austerity, and thus he came to this realization. We must therefore take all knowledge from Brahmā, who became perfect by his tapasya.