Mahabharata — Anushasana Parva, Shloka 163
Śiva-nāmānukīrtana-prastāvaḥ
Prologue to the praise of Śiva and the Upamanyu testimony
अरूपस्याद्यरूपस्य अतिरूपाद्यरूपिण: । अनाट्यन्तमजस्यान्तं वेत्स्यते को5स्य तत्त्वतः
arūpasyādyarūpasya atirūpādyarūpiṇaḥ | anāṭyantamajas yāntaṃ vetsyate ko 'sya tattvataḥ ||
वे रूपरहित हैं—और रूपरहितों में भी आद्य हैं; रूप से परे हैं, फिर भी समस्त रूपों के कारण हैं। वे अजन्मा हैं, जिनका न आदि है न अन्त। उनके तत्त्व को यथार्थतः कौन जान सकता है?
वासुदेव उवाच
Educational Q&A
The verse stresses the transcendence of the supreme reality: it is beyond form and conceptual limits, unborn and without beginning or end; therefore complete knowledge of its essence is beyond ordinary cognition, encouraging humility and reverence.
Vāsudeva is describing the nature of the highest divine principle (understood in this context as Mahādeva/Śiva): emphasizing its formlessness, primacy, and beginningless-endless character, and concluding that no one can fully grasp its true essence.