Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 3 · Name Letters and Chakras
युद्धजयार्णवः (चक्राणि)
जकारं विन्दुसंयुक्तमोंकारेण समन्वितम् ।धकारोदरमध्यस्थं वकारेण निबोधितम् ॥ ३९ ॥
In the full Agni Purana this is chapter 133, verse 39.
Take the letter ja with a dot, joined with Om. Set it in the belly of the letter dha. Awaken it with the letter va.
Simple meaning: Write ja with a dot and Om inside the letter dha, and awaken it with va.
चन्द्रसंपुटमध्यस्थं सर्वदुष्टविमर्दकम् ।
This figure inside a moon-shaped ring crushes evil. Or write the name and the purpose in the centre.
पूर्वे दले तथोंकारं स्वदक्षे चोत्तरे लिखेत् ।
Write Om on the east petal, Hum on the next petals and the vowels on the sixteen petals.
चतुस्त्रिंशद्दले काद्यान्बाह्ये मन्त्रं च मृत्युजित् ।
Write the letters on thirty-four petals with the Mrityunjaya spell outside, on birch bark with rochana and saffron.