The Great Epic of the Bhārata dynasty 6.41.84

6.41.84

vāsudevastu rādheyamāhave'bhijagāma vai |
tata enamuvācedaṃ pāṇḍavārthe gadāgrajaḥ || 84 ||

'Sanjaya continued, "Having obtained the permission of his maternal uncle, the ruler of the Madra, the son of Kunti, surrounded by his brothers, came out of that vast army. Vasudeva then went to Radha's son on the field of battle. And the elder brother of Gada, for the sake of the Pandavas, then said to Karna,--It hath been heard by me, O Karna, that from hatred of Bhishma thou wilt not fight. Come to our side, O son of Radha, and (stay with us) as long as Bhishma is not slain. After Bhishma is slain, O son of Radha, thou mayst then again engage in battle on Duryodhana's side, if thou hast no preference for any of the parties.--'