BṚHADĀRAṆYAKA UPANISHAD · 4.4.5

स वा अयम् आत्मा ब्रह्म विज्ञानमयो मनोमयो प्राणमयश् चक्षुर्मयः श्रोत्रमयः पृथिवीमय आपोमयो वायुमय आकाशमयस् तेजोमयो ऽतेजोमयः काममयो ऽकाममयः क्रोधमयो ऽक्रोधमयो धर्ममयो ऽधर्ममयः सर्वमयः ।
तद् यद् एतद् इदंमयो ऽदोमय इति ।
यथाकारी यथाचारी तथा भवति ।
साधुकारी साधुर् भवति ।
पापकारी पापो भवति ।
पुण्यः पुण्येन कर्मणा पापः पापेन ।
अथो खल्व् आहुः ।
काममय एवायं पुरुष इति ।
स यथाकामो भवति तत्क्रतुर् भवति ।
यत्क्रतुर् भवति तत् कर्म कुरुते ।
यत् कर्म कुरुते तद् अभिसंपद्यते ॥

sa vā ayam ātmā brahma vijñānamayo manomayo prāṇamayaś cakṣurmayaḥ śrotramayaḥ pṛthivīmaya āpomayo vāyumaya ākāśamayas tejomayo ’tejomayaḥ kāmamayo ’kāmamayaḥ krodhamayo ’krodhamayo dharmamayo ’dharmamayaḥ sarvamayaḥ ।
tad yad etad idaṃmayo ’domaya iti ।
yathākārī yathācārī tathā bhavati ।
sādhukārī sādhur bhavati ।
pāpakārī pāpo bhavati ।
puṇyaḥ puṇyena karmaṇā pāpaḥ pāpena ।
atho khalv āhuḥ ।
kāmamaya evāyaṃ puruṣa iti ।
sa yathākāmo bhavati tatkratur bhavati ।
yatkratur bhavati tat karma kurute ।
yat karma kurute tad abhisaṃpadyate ॥

'That Self is indeed Brahman, consisting of knowledge, mind, life, sight, hearing, earth, water, wind, ether, light and no light, desire and no desire, anger and no anger, right or wrong, and all things. Now as a man is like this or like that, according as he acts and according as he behaves, so will he be:--a man of good acts will become good, a man of bad acts, bad. He becomes pure by pure deeds, bad by bad deeds. 'And here they say that a person consists of desires. And as is his desire, so is his will; and as is his will, so is his deed; and whatever deed he does, that he will reap.

F. Max Müller · The Upanishads, Sacred Books of the East 15 (1884)