Shiva Purana
पुरस्तात्स्तंभरूपेण पश्चाद्रू पेण चार्भकौ । ब्रह्मत्वं निष्कलं प्रोक्तमीशत्वं सकलं तथा ३१ ।
Dear sons, first in the form of the column and afterwards in this embodied form I have expounded to you my formless Brahma-hood, and embodied Īśa-hood.
english translation
purastAtstaMbharUpeNa pazcAdrU peNa cArbhakau । brahmatvaM niSkalaM proktamIzatvaM sakalaM tathA 31 ।
hk transliteration by Sanscript