Rudra-Śiva: Names, Two Natures, and the Logic of Epithets (रुद्रनाम-बहुरूपत्व-प्रकरणम्)
फलमूलाशनं वायुराप: शैवलभक्षणम् | ऋषीणां नियमा होते यैर्जयन्त्यजितां गतिम्
phalamūlāśanaṃ vāyur āpaḥ śaivalabhakṣaṇam | ṛṣīṇāṃ niyamā hote yair jayanty ajitāṃ gatim ||
Śrī Maheśvara said: Living on fruits and roots, subsisting on air, drinking only water, and even eating aquatic plants—these are the disciplines observed by seers. By such restraints they conquer the otherwise unconquerable course of existence, mastering the difficult path through self-control and austerity.
श्रीमहेश्वर उवाच
The verse teaches that rigorous self-restraint and austere observances (niyamas)—especially disciplined control of food and bodily needs—are powerful means by which sages overcome the hardest spiritual obstacles and master the difficult path of existence.
Maheśvara is describing the kinds of ascetic practices followed by ṛṣis—living on fruits and roots, subsisting on air, taking only water, or eating algae—as exemplary disciplines that enable spiritual conquest of an otherwise unconquerable 'gati' (course/goal).