Rudra-prasava-varṇana
The Manifestation and Naming of Rudra / Nīlalohita
तनुरुग्रात्मिका सा तु तेनोग्रो दीक्षितः स्मृतः / यत्तु संकल्पकं तस्य प्रजास्विह समास्थितम्
tanurugrātmikā sā tu tenogro dīkṣitaḥ smṛtaḥ / yattu saṃkalpakaṃ tasya prajāsviha samāsthitam
That form is of Ugra nature; therefore he is remembered as one initiated as Ugra. And his power of saṅkalpa—his sacred resolve—abides here among the creatures.