Bṛhadāraṇyaka Upaniṣad ("Great Forest Teaching") 2.4.5

2.4.5

sa hovāca na vā are patyuḥ kāmāya patiḥpriyo bhavatyātmanastu kāmāya patiḥ priyo bhavati | na vā are jāyāyai kāmāyajāyā priyā bhavatyātmanastu kāmāya jāyā priyā bhavati | na vā are putrāṇāṃkāmāya putrāḥ priyā bhavantyātmanastu kāmāya putrāḥ priyā bhavanti | na vā are vittasya kāmāya vittaṃ priyaṃ bhavatyātmanastu kāmāya vittaṃ priyaṃ bhavati | navā are brahmaṇaḥ kāmāya brahma priyaṃ bhavatyātmanastu kāmāya brahma priyaṃ bhavati | na vā are kṣatrasya kāmāya kṣatraṃ priyaṃ bhavatyātmanastu kāmāya kṣatraṃ priyaṃ bhavati | na vā are lokānāṃ kāmāya lokāḥ priyā bhavantyātmanastu kāmāyalokāḥ priyā bhavanti | na vā are devānāṃ kāmāya devāḥ priyā bhavantyātmanastu kāmāya devāḥ priyā bhavanti | na vā are bhūtānāṃ kāmāya bhūtāni priyāṇi bhavantyātmanastu kāmāya bhūtāni priyāṇi bhavanti | na vā are sarvasya kāmāya sarvaṃ priyaṃ bhavatyātmanastu kāmāya sarvaṃ priyaṃbhavati | ātmā vā are draṣṭavyaḥ śrotavyo mantavyo nididhyāsitavyo maitreyyātmano vā are darśanena śravaṇena matyā vijñānenedam̐ sarvaṃ viditam

And he said: 'Verily, a husband is not dear, that you may love the husband; but that you may love the Self, therefore a husband is dear.
'Verily, a wife is not dear, that you may love the wife; but that you may love the Self, therefore a wife is dear.
'Verily, sons are not dear, that you may love the sons; but that you may love the Self, therefore sons are dear.
'Verily, wealth is not dear, that you may love wealth; but that you may love the Self, therefore wealth is dear.
'Verily, the Brahman-class is not dear, that you may love the Brahman-class; but that you may love the Self, therefore the Brahman-class is dear.
'Verily, the Kshatra-class is not dear, that you may love the Kshatra-class; but that you may love the Self, therefore the Kshatra-class is dear.
'Verily, the worlds are not dear, that you may love the worlds; but that you may love the Self, therefore the worlds are dear.
'Verily, the Devas are not dear, that you may love the Devas; but that you may love the Self, therefore the Devas are dear.
'Verily, creatures are not dear, that you may love the creatures; but that you may love the Self, therefore are creatures dear.
'Verily, everything is not dear that you may love everything; but that you may love the Self, therefore everything is dear.
'Verily, the Self is to be seen, to be heard, to be perceived, to be marked, O Maitreyî! When we see, hear, perceive, and know the Self, then all this is known.