Shloka 4
समुद्रपानम् (Samudra-pānam) — Maitrāvaruṇi Drains the Ocean; Devas Seek a Means to Refill It
क्षीणेषु च ब्राह्मणेषु पृथिवी क्षयमेष्यति । ततः पृथिव्यां क्षीणायां त्रिदिवं क्षयमेष्यति,ब्राह्मणोंके नष्ट होनेपर सारी पृथ्वी नष्ट हो जायगी और पृथ्वीका नाश होनेपर स्वर्ग भी नष्ट हो जायगा
kṣīṇeṣu ca brāhmaṇeṣu pṛthivī kṣayam eṣyati | tataḥ pṛthivyāṃ kṣīṇāyāṃ tridivaṃ kṣayam eṣyati ||
婆罗门一旦衰微，大地便将走向败坏；而大地既败坏，天界亦将随之衰落。
लोगश उवाच
Educational Q&A
The verse teaches that the welfare of the world is tied to the protection of dharma as embodied by Brahmins—keepers of Vedic learning, rites, and ethical norms. When that sustaining institution collapses, society and even the cosmic reward-system symbolized by heaven is said to deteriorate.
Lomaśa is speaking and emphasizing to his listeners that neglecting or destroying Brahmins leads to cascading ruin: first the earth (worldly order) declines, and then heaven (the sphere of merit and divine order) also declines.