Shiva Purana
अरुद्रो वा सरुद्रो वा सूक्तेन शिवमर्चयेत् ॥ यः सकृत्पतितो वापिमूढो वा मुच्यते नरः ॥ ९ ॥
Whether a man is a follower of Rudra or not, whether he is fallen or deluded if he worships but once with Rudra Sūkta he is liberated.
english translation
arudro vA sarudro vA sUktena zivamarcayet ॥ yaH sakRtpatito vApimUDho vA mucyate naraH ॥ 9 ॥
hk transliteration by Sanscript