Shiva Purana
पुरातनाश्च राजानो विप्रा वैश्याश्च सत्तमाः ॥ इदं श्रुत्वा पंचकृत्वो धिया सिद्धिं परां गताः ॥ ५२ ॥
Ancient kings, brahmins and excellent Vaiśyas have attained great Siddhis by listening to this with attention, five times.
english translation
purAtanAzca rAjAno viprA vaizyAzca sattamAH ॥ idaM zrutvA paMcakRtvo dhiyA siddhiM parAM gatAH ॥ 52 ॥
hk transliteration by Sanscript