Mahabharata 4.39.16

न कुर्यां कर्म बीभत्सं युध्यमानः कथंचनतेन देवमनुष्येषु बीभत्सुरिति मां विदुः

na kuryāṃ karma bībhatsaṃ yudhyamānaḥ kathaṃcanatena devamanuṣyeṣu bībhatsuriti māṃ viduḥ

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