Mahabharata 12.305.13

शीर्णनाभि यथा चक्रं छिद्रं सोमं प्रपश्यतितथैव च सहस्रांशुं सप्तरात्रेण मृत्युभाक्

śīrṇanābhi yathā cakraṃ chidraṃ somaṃ prapaśyatitathaiva ca sahasrāṃśuṃ saptarātreṇa mṛtyubhāk

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