Mahabharata 1.114.20

आत्मना च महाबाहुरेकपादस्थितोऽभवत्उग्रं स तप आतस्थे परमेण समाधिना

ātmanā ca mahābāhurekapādasthito'bhavatugraṃ sa tapa ātasthe parameṇa samādhinā

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