Shiva Purana

siva.sh/siva-purana/uma-samhita/48/5

निशुंभशुंभौ दितिजान्निदेश्य तान्रथाधिरूढौ निरयां बभूवतुः ।। बलान्यनूखुर्बलिनोस्तयोर्धराद्विनाशवन्तः शलभा इवोत्थिताः।। ५।।

sanskrit

After ordering the demons, Śumbha and Niśumbha mounted on their chariots and set out. Their armies too followed them like swarms of moths rising up from a mountain definitely for their destruction.

english translation

nizuMbhazuMbhau ditijAnnidezya tAnrathAdhirUDhau nirayAM babhUvatuH || balAnyanUkhurbalinostayordharAdvinAzavantaH zalabhA ivotthitAH|| 5||

hk transliteration by Sanscript