Bhagavad Gita Chapter 1.14
tataḥ śvetair hayair yukte
mahati syandane sthitau
mādhavaḥ pāṇḍavaś caiva
divyau śańkhau pradadhmatuḥ
Translation
On the other side, both Lord Krishna and Arjuna, stationed on a great chariot drawn by white horses, sounded their transcendental conchshells.