Shloka 43
Pratyakṣa–Āgama–Ācāra: Doubt, Proof, and the Practice of Dharma (प्रत्यक्ष–आगम–आचारविचारः)
अग्नियोगवह्ो ग्रीष्मे विधिदृष्टेन कर्मणा । चीर्त्वा द्वादशवर्षाणि राजा भवति पार्थिव:
agnīyogavaho grīṣme vidhidṛṣṭena karmaṇā | cīrtvā dvādaśavarṣāṇi rājā bhavati pārthivaḥ ||
摩醯首罗说道：若有人在盛夏酷热之时，依经教所定之仪轨修行“五火”之苦行，并持守此行满十二年，则来世将再生为统御大地之王——以严谨自制之苦行为因，得世间王权之果。
श्रीमहेश्वर उवाच
Educational Q&A
Austerity yields results only when performed with disciplined adherence to prescribed rule (vidhi). Sustained, lawful tapas—here, the five-fire observance in summer—produces a concrete karmic fruit: rebirth into worldly sovereignty (kingship).
Śrī Maheśvara is describing the merit (phala) of a specific ascetic observance: practicing the fire-related austerity during summer according to scriptural procedure and maintaining it for twelve years, which results in being reborn as a ruler of the earth.