Vaisesika Sūtra 2.2.07

तस्य द्रव्यत्वनित्यत्वे वायुना व्याख्याते ॥७॥

tasya dravyatvanityatve vāyunā vyākhyāte ॥7॥

[तस्य (tasya) - of that; द्रव्यत्वनित्यत्वे (dravyatvanityatve) - eternal nature, protentiality to flow; वायुना (vāyunā) - by air; व्याख्याते (vyākhyāte) - it is explained;]

By that, the nature of air, in terms of its potentiality to flow and eternality, are explained.