CHĀNDOGYA UPANISHAD · 3.11.1

अथ तत ऊर्ध्व उदेत्य नैवोदेता नास्तम् एतैकल एव मध्ये स्थाता ।
तद् एष श्लोकः ॥

atha tata ūrdhva udetya naivodetā nāstam etaikala eva madhye sthātā ।
tad eṣa ślokaḥ ॥

When from thence he has risen upwards, he neither rises nor sets. He is alone, standing in the centre. And on this there is this verse:

F. Max Müller · The Upanishads, Sacred Books of the East 1 (1879)