Śatapatha Brāhmaṇa ("of a hundred paths") 7.3.2.13

7.3.2.13

yadvevāvaghrāpayati | asau vā āditya eṣo 'śva ima u lokā etāḥ svayamātṛṇāstadyadavaghrāpayatyasāveva tadāditya imāṃlokāntsūtre samāvayate tadyattatsūtramupari tasya bandhuḥ

And, again, why he makes it smell;--that horse is yonder sun, and those naturally-perforated (bricks) are these worlds; and even as he makes it smell, so yonder sun strings these worlds to himself on a thread. And as to that thread, the significance of that (will be explained) further on.