MUṆḌAKA UPANISHAD · 2.1.1

तदेतत्सत्यं
यथा सुदीप्तात्पावकाद्विस्फुलिङ्गाः
सहस्रशः प्रभवन्ते सरूपाः ।
तथाऽक्षराद्विविधाः सोम्य भावाः
प्रजायन्ते तत्र चैवापियन्ति ॥ १॥

tadetatsatyaṃ
yathā sudīptātpāvakādvisphuliṅgāḥ
sahasraśaḥ prabhavante sarūpāḥ ।
tathā’kṣarādvividhāḥ somya bhāvāḥ
prajāyante tatra caivāpiyanti ॥ 1॥

This is That, the Truth of things: as from one high-kindled fire thousands of different sparks are born and all have the same form of fire, so, O fair son, from the immutable manifold becomings are born and even into that they depart.

Sri Aurobindo · CWSA 18, p. 137