Revākhaṇḍa ascribed to the Vāyupurāṇa (RKV) 189.15

189.15

pāvanāya jagaddhetoḥ sthito yasmācchaśiprabhaḥ /
atastu nṛpaśārdūla śveta ityābhidhīyate //

because he stands with the brilliance of the moon for the purification and sake of the world,
therefore, O tiger among kings, he is called Śveta;