Mahabharata — Anushasana Parva, Shloka 18
Pratyakṣa–Āgama–Ācāra: Doubt, Proof, and the Practice of Dharma (प्रत्यक्ष–आगम–आचारविचारः)
ब्रह्मलोक॑ महापुण्यं सोमलोकं च शाश्वतम् । गच्छन्ति मुनयः सिद्धा: सत्यधर्मव्यपाश्रया:,वे मुनि सत्यधर्मका आश्रय लेनेवाले और सिद्ध होते हैं, अतः महान् पुण्यमय ब्रह्मलोक तथा सनातन सोमलोकमें जाते हैं
brahmalokaṁ mahāpuṇyaṁ somalokaṁ ca śāśvatam | gacchanti munayaḥ siddhāḥ satyadharmavyapāśrayāḥ ||
摩醯湿伐罗说道：“诸牟尼——已臻成就之者（siddha），依止真实（satya）与正法（dharma）——得至大福德之梵天界（Brahmaloka），亦得至永恒之苏摩界（Somaloka）。”
श्रीमहेश्वर उवाच
Educational Q&A
Those who firmly rely on satya (truthfulness) and dharma (righteous conduct) become spiritually accomplished (siddha) and attain exalted, enduring realms such as Brahmaloka and Somaloka; ethical integrity is presented as the causal path to higher attainment.
Maheshvara is describing the destiny of sages who are established in truth and dharma: they proceed to highly meritorious celestial/spiritual worlds—Brahmaloka and the eternal Somaloka—illustrating the fruits of disciplined, righteous living.