Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 3 · Name Letters and Chakras
युद्धजयार्णवः (चक्राणि)
वायौ संवेष्टयित्वा च शत्रुं हन्तीशसंमुखम् ।तिथिराहुं प्रवक्ष्यामि पूर्णिमाऽऽग्नेयगोचरे ॥ १० ॥
In the full Agni Purana this is chapter 142, verse 10.
and the north-west. Going round like this, he kills the enemy who faces the north-east. Now I will tell the Rahu of the tithi (moon day). On the full moon, he is in the south-east.
Simple meaning: Serpent Rahu circles and kills the enemy. At full moon, Tithi Rahu is in the south-east.
अमावास्यां वायवे च राहुः संमुखशत्रुहा ।
At the new moon Rahu is in the north-west. The letters are split into groups by direction.
शुक्ले त्यजेत्कुजगुणान्धाद्या मान्ताश्च पूर्वतः ।
In the bright half, avoid certain things. Letters are set in the east and north. Avoid the look of the moon day.
पूर्वाश्च दक्षिणास्तिस्रो रेखा वै मूलभेदके ।
Draw three lines each way. Write the signs from the Sun's sign. Under the look, loss; otherwise victory.