SB 8.10.41
balir mahendram dasabhis
tribhir airavatam saraih
caturbhis caturo vahan
ekenaroham arcchayat
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Maharaja Bali then attacked Indra with ten arrows and attacked Airavata, Indra’s carrier elephant, with three arrows. With four arrows he attacked the four horsemen guarding Airavata’s legs, and with one arrow he attacked the driver of the elephant.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The word vahan refers to the soldiers on horseback who protected the legs of the carrier elephants. According to the system of military arrangement, the legs of the elephant bearing the commander were also protected.