Shiva Purana
तदुपर्य्यमरेशं च महाकालं च मध्यतः ॥ तन्मस्तकस्थं दण्डं च तत ईश्वरमालिखेत् ॥ १० ॥
Beyond that is the Lord of the gods and Mahakala in the middle Then write the Lord on the staff on his head.
english translation
taduparyyamarezaM ca mahAkAlaM ca madhyataH ॥ tanmastakasthaM daNDaM ca tata IzvaramAlikhet ॥ 10 ॥
hk transliteration by Sanscript