Vaisesika Sūtra 7.1.20

नित्यं परिमण्डलम् ॥२०॥

nityaṃ parimaṇḍalam ॥20॥

[नित्यं (nityaṃ) - eternal; always; परिमण्डलम् (parimaṇḍalam) - that which extends around in a circle or sphere;]

The eternality extends around in a circle or sphere.