Chandogya Upanishad 7.26

tasya ha vā etasyaivaṃ paśyata evaṃ manvānasyaivaṃ vijānata ātmataḥ prāṇa ātmata āśātmataḥ smara ātmata ākāśa ātmatas teja ātmata āpa ātmata āvirbhāvatirobhāvāv ātmato 'nnam ātmato balam ātmato vijñānam ātmato dhyānam ātmataś cittam ātmataḥ saṃkalpa ātmato mana ātmato vāg ātmato nāmātmato mantrā ātmataḥ karmāṇy ātmata evedaṃ sarvam iti

'To him who sees, perceives, and understands this the spirit (prâna) springs from the Self, hope springs from the Self, memory springs from the Self; so do ether, fire, water, appearance and disappearance, food, power, understanding, reflection, consideration, will, mind, speech, names, sacred hymns, and sacrifices—aye, all this springs from the Self.

tad eṣa ślokaḥ na paśyo mṛtyuṃ paśyati na rogaṃ nota duḥkhatām sarvaṃ ha paśyaḥ paśyati sarvam āpnoti sarvaśaḥ iti sa ekadhā bhavati tridhā bhavati pañcadhā saptadhā navadhā caiva punaś caikādaśa smṛtaḥ śataṃ ca daśa caikaś ca sahasrāṇi ca viṃśatiḥ āhāraśuddhau sattvaśuddhiḥ sattvaśuddhau dhruvā smṛtiḥ smṛtilambhe sarvagranthīnāṃ vipramokṣaḥ tasmai mṛditakaṣāyāya tamasas pāraṃ darśayati bhagavān sanatkumāraḥ taṃ skanda ity ācakṣate

'There is this verse, "He who sees this, does not see death, nor illness, nor pain; he who sees this, sees everything, and obtains everything everywhere. '"He is one (before creation), he becomes three (fire, water, earth), he becomes five, he becomes seven, he becomes nine; then again he is called the eleventh, and hundred and ten and one thousand and twenty." 'When the intellectual aliment has been purified, the whole nature becomes purified. When the whole nature has been purified, the memory becomes firm. And when the memory (of the Highest Self) remains firm, then all the ties (which bind us to a belief in anything but the Self) are loosened. 'The venerable Sanatkumâra showed to Nârada, after his faults had been rubbed out, the other side of darkness. They call Sanatkumâra Skanda, yea, Skanda they call him.'