The Bhagavad Gita with Commentaries of Ramanuja, Madhva, Shankara and Others.
Bhagavad Gita 1.15
http://www.bhagavad-gita.us/articles/645/1/Bhagavad-Gita-115/Page1.html
By Bhagavan Sri Krishna
 

Text 15

pancajanyam hrsikeso
devadattam dhananjayah
paundram dadhmau maha-sankham
bhima-karma vrkodarah

Translation

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. 

Commentary by Srila Prabhupada 

Lord Krishna is referred to as Hrishikesha in this verse because He is the owner of all senses. The living entities are part and parcel of Him, and therefore the senses of the living entities are also part and parcel of His senses. The impersonalists cannot account for the senses of the living entities, and therefore they are always anxious to describe all living entities as senseless, or impersonal. The Lord, situated in the hearts of all living entities, directs their senses. But He directs in terms of the surrender of the living entity, and in the case of a pure devotee He directly controls the senses. Here on the Battlefield of Kurukshetra the Lord directly controls the transcendental senses of Arjuna, and thus His particular name of Hrishikesha. The Lord has different names according to His different activities. For example, His name is Madhusudana because He killed the demon of the name Madhu; His name is Govinda because He gives pleasure to the cows and to the senses; His name is Vasudeva because He appeared as the son of Vasudeva; His name is Devaki-nandana because He accepted Devaki as His mother; His name is Yashoda-nandana because He awarded His childhood pastimes to Yashoda at Vrindavana; His name is Partha-sarathi because He worked as charioteer of His friend Arjuna. Similarly, His name is Hrishikesha because He gave direction to Arjuna on the Battlefield of Kurukshetra.

Arjuna is referred to as Dhananjaya in this verse because he helped his elder brother in fetching wealth when it was required by the king to make expenditures for different sacrifices. Similarly, Bhima is known as Vrkodara because he could eat as voraciously as he could perform herculean tasks, such as killing the demon Hidimba. So the particular types of conchshell blown by the different personalities on the side of the Pandavas, beginning with the Lord’s, were all very encouraging to the fighting soldiers. On the other side there were no such credits, nor the presence of Lord Krishna, the supreme director, nor that of the goddess of fortune. So they were predestined to lose the battle—and that was the message announced by the sounds of the conchshells.

Commentary by Sri Visvanatha Cakravarti Thakur

Please see text 16 for Sri Visvanatha Cakravarti Thakur's combined commentary to texts 15 and 16.