Vaisesika Sūtra 5.1.14

तृणे कर्म वायुसंयोगात् ॥१४॥

tṛṇe karma vāyusaṁyogāt ॥14॥

[तृणे (tṛṇe) - in the grass; कर्म (karma) - action; वायु-संयोगात् (vāyu-saṁyogāt) - due to conjunction with wind;]

Action in grass arises from conjunction with the wind.