KAṬHA UPANISHAD · 2.3.5

यथाऽऽदर्शे तथाऽऽत्मनि यथा स्वप्ने तथा पितृलोके ।
यथाऽप्सु परीव ददृशे तथा गन्धर्वलोके
छायातपयोरिव ब्रह्मलोके ॥ ५॥

yathā’’darśe tathā’’tmani yathā svapne tathā pitṛloke ।
yathā’psu parīva dadṛśe tathā gandharvaloke
chāyātapayoriva brahmaloke ॥ 5॥

In the self one seeth God as in a mirror but as in a dream in the world of the fathers, and as in water one seeth the surface of an object, so one seeth Him in the world of the Gandharvas; but He is seen as light and shade in the heaven of the Spirit.

Sri Aurobindo · CWSA 18, p. 124