Bṛhadāraṇyaka Upaniṣad ("Great Forest Teaching") 4.4.6

4.4.6

tadeṣa śloko bhavati | tadeva saktaḥ saha karmaṇaiti liṅge mano yatra niṣaktamasya prātyāntaṃ karmaṇastasya yatkiṃceha karotyayam | tasmāllokātpunaraityasmai lokāya karmaṇa iti nu kāmayamāno'thākāmayamāno yo'kāmo niṣkāma āptakāma ātmakāmo na tasya prāṇā utkrāmanti brahmaiva sanbrahyāpyeti

'And here there is this verse: "To whatever object a man's own mind is attached, to that he goes strenuously together with his deed; and having obtained the end (the last results) of whatever deed he does here on earth, he returns again from that world (which is the temporary reward of his deed) to this world of action."
'So much for the man who desires. But as to the man who does not desire, who, not desiring, freed from desires, is satisfied in his desires, or desires the Self only, his vital spirits do not depart elsewhere,--being Brahman, he goes to Brahman.