Shiva Purana
विद्यापादं समारूढं वह्निमण्डलमध्यगम् ॥ द्वितीयं शिवबीजेषु कलास्वष्टकलान्वितम् ॥ ३४ ॥
He rode on the feet of Vidyā and was in the midst of a circle of fire. The second is composed of eight arts in the seeds of Lord Shiva.
english translation
vidyApAdaM samArUDhaM vahnimaNDalamadhyagam ॥ dvitIyaM zivabIjeSu kalAsvaSTakalAnvitam ॥ 34 ॥
hk transliteration by Sanscript