Mahabharata 2.35.7

2.35.7

kṣatriyaḥ kṣatriyaṃ jitvā raṇe raṇakṛtāṃ varaḥ |
yo muñcati vaśe kṛtvā gururbhavati tasya saḥ || 7 ||

"Bhishma also, after this, said,--He that approveth not the worship offered unto Krishna, the oldest one in the universe, deserveth neither soft words nor conciliation. The chief of warriors of the Kshatriya rare who having overcome a Kshatriya in battle and brought him under his power, setteth him free, becometh the guru (preceptor or master) of the vanquished one. I do not behold in this assembly of kings even one ruler of men who hath not been vanquished in battle by the energy of this son of the Satwata race. This one (meaning Krishna) here, of undefiled glory, deserveth to be worshipped not by ourselves alone, but being of mighty arms, he deserveth to be worshipped by the three worlds also. Innumerable warriors among Kshatriyas have been vanquished in battle by Krishna. The whole universe without limit is established in him of the Vrishni race. Therefore do we worship Krishna amongst the best and the oldest, and not others. It behoveth thee not to say so. Let thy understanding be never so. I have, O king, waited upon many persons that are old in knowledge. I have heard from all those wise men, while talking; of the numerous much-regarded attributes of the accomplished Sauri. I have also heard many times all the acts recited by people that Krishna of great intelligence hath performed since his birth.