Mahabharata 5.154.6

5.154.6

vaiśaṃpāyana uvāca |
āpaddharmārthakuśalo mahābuddhiryudhiṣṭhiraḥ |
sarvānbhrātṝnsamānīya vāsudevaṃ ca sātvatam |
uvāca vadatāṃ śreṣṭhaḥ sāntvapūrvamidaṃ vacaḥ || 6 ||

"Vaisampayana said, 'When news was received of this, Yudhishthira endued with great intelligence and well-acquainted with what should be done in view of dangers and calamities summoned all his brothers and also the eternal Vasudeva (to his presence). And that foremost of speakers then said in a mild voice, 'Make your rounds among the soldiers, and remain carefully, casing yourselves in mail. Our first encounter will be with our grandsire. Look ye for (seven) leaders for the seven Akshauhinis of my troops.'