Shiva Purana
अघोरास्त्रं च शैवानां रक्षाहेतुरनुत्तमम् ॥ तच्च तत्प्रभवं मत्वा तत्परो भव नान्यथा ॥ ४७ ॥
The excellent Aghora missile affording protection to the devotees of Śiva originates from this mantra. Considering this, be devoted to it and not otherwise.
english translation
aghorAstraM ca zaivAnAM rakSAheturanuttamam ॥ tacca tatprabhavaM matvA tatparo bhava nAnyathA ॥ 47 ॥
hk transliteration by Sanscript