Mahabharata 1.65.23

असावादित्यसंकाशो विश्वामित्रो महातपाःतप्यमानस्तपो घोरं मम कम्पयते मनः

asāvādityasaṃkāśo viśvāmitro mahātapāḥtapyamānastapo ghoraṃ mama kampayate manaḥ

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