Brihadaranyaka Upanishad 1.4.8

1.4.8

tadetatpreyaḥ putrātpreyo vittātpreyo'nyasmātsarvasmādantarataraṃ yadayamātmā | sa yo'nyamātmanaḥ priyaṃ bruvāṇaṃ brūyāt priyam̐ rotsyatītīśvaro ha tathaiva syādātmānameva priyamupāsīta sa ya ātmānameva priyamupāste na hāsya priyaṃ pramāyukaṃ bhavati

This Self is dearer than a son, dearer than wealth, dearer than everything else, and is innermost. Should a person (holding the Self as dear) say to one calling anything else dearer than the Self, ‘(What you hold) dear will die’—he is certainly competent (to say so)—it will indeed come true. One should meditate upon the Self alone as dear. Of him who meditates upon the Self alone as dear, the dear ones are not mortal.