|Chapter 1: Observing the Armies on the Battlefield of Kurukshetra|
paundram dadhmau maha-sankham
Lord Krishna blew His conchshell, called Pancajanya; Arjuna blew his, the Devadatta; and Bhima, the voracious eater and performer of herculean tasks, blew his terrific conchshell, called Paundra.
Srila Prabhupada notes, "The Lord has different names according to different pastimes." It is interesting to note the way the names of Krishna and Arjuna are used to indicate certain quality that is relevant to that stage of discussion. For instance here Krishna is addressed as "Hrishikesha," which means the controller of senses. Srila Prabhupada states that this is significant because the impersonalists deny their own senses in an attempt to deny God. But Krishna situated as Supersoul in everyone's heart controls their senses in proportion to their extend of surrender. A pure devotee like Arjuna is completely surrendered to Krishna and thus Krishna has taken complete control of his senses. And for one who is under the control of Krishna, there is no question of defeat.
Arjuna is referred to as "Dhananjaya," which means the "conqueror of wealth." Sanjaya is discreetly indicating that Arjuna in the past has won great victories over formidable kings. Here he is present, directly under the control of the Supreme Lord Krishna. Victory is therefore assured for them.
Please read the Sanskrit Verse and the Prabhupada's Purport.