Mbh 4.33.3c

And sorely afflicted with that kicking, the king of Trigartas became senseless. And when the king of the Trigartas deprived of his car, had been seized thus, the whole Trigarta army stricken with panic, broke and fled in all directions, and the mighty sons of Pandu, endued with modesty and observant of vows and relying on the might of their own arms, after having vanquished Susarman, and rescued the kine as well as other kinds of wealth and having thus dispelled Virata’s anxiety, stood together before that monarch. And Bhimasena then said, ‘This wretch given to wicked deeds doth not deserve to escape me with life. But what can I do? The king is so lenient!’ And then taking Susarman by the neck as he was lying on the ground insensible and covered with dust, and binding him fast, Pritha’s son Vrikodara placed him on his car, and went to where Yudhishthira was staying in the midst of the field. And Bhima then showed Susarman unto the monarch. And beholding Susarman in that plight, that tiger among men king Yudhishthira smilingly addressed Bhima--that ornament of battle,--saying, ‘Let this worst of men be set free.’ Thus addressed, Bhima spoke unto the mighty Susarman, saying, ‘If, O wretch, thou wishest to live, listen to those words of mine. Thou must say in every court and assembly of men,--“I am a slave.” On this condition only I will grant thee thy life. Verily, this is the law about the vanquished.’ Thereupon his elder brother affectionately addressed Bhima, saying, ‘If thou regardest us as an authority, liberate this wicked wight. He hath already become king Virata’s slave.’ And turning then to Susarman, he said, ‘Thou art freed. Go thou a free man, and never act again in this way.’”