Shiva Purana

siva.sh/siva-purana/rudra-samhita/4/32

स एवमादाय मायां स्वां त्रिधा भवति रूपतः ।। ब्रह्मविष्णुमहेशात्मा निर्गुणोऽनिर्गुणोऽपि सः ।। ३२ ।।

sanskrit

He is both Saguṇa and Nirguṇa (with and without attributes). He Himself availing of his own Māyā manifests into three forms—Brahma, Viṣṇu, and Maheśa.

english translation

sa evamAdAya mAyAM svAM tridhA bhavati rUpataH || brahmaviSNumahezAtmA nirguNo'nirguNo'pi saH || 32 ||

hk transliteration by Sanscript