Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 4
Sanskrit:
दुरुक्तौ कलिराधत्त भयं मृत्युं च सत्तम ।तयोश्च मिथुनं जज्ञे यातना निरयस्तथा ॥ ४ ॥
ITRANS:
duruktau kalir ādhattabhayaṁ mṛtyuṁ ca sattamatayoś ca mithunaṁ jajñeyātanā nirayas tathā
Translation:
O greatest of all good men, by the combination of Kali and Harsh Speech were born children named Mṛtyu (Death) and Bhīti (Fear). From the combination of Mṛtyu and Bhīti came children named Yātanā (Excessive Pain) and Niraya (Hell).