Mahabharata 13.135.65

गभस्तिनेमिः सत्त्वस्थः सिंहो भूतमहेश्वरःआदिदेवो महादेवो देवेशो देवभृद्गुरुः

gabhastinemiḥ sattvasthaḥ siṃho bhūtamaheśvaraḥādidevo mahādevo deveśo devabhṛdguruḥ

Our plain-language meaning of this verse is waiting for scholar review.