Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · War Astrology: Yogas, Nakshatras
युद्धजयार्णवः (योगाः नक्षत्राणि)
राहुचक्रे च सप्तोर्ध्वमधः सप्त च संलिखेत् ।वाय्वग्न्योश्चैव नैर्ऋत्ये पूर्णिमाऽऽग्नेयभागतः ॥ १० ॥
In the full Agni Purana this is chapter 123, verse 10.
In the Rahu wheel, draw seven lines above and seven below. Mark the north-west, the south-east and the south-west. The full moon day starts from the south-east side.
Simple meaning: In the Rahu wheel, seven lines are drawn above and seven below, and the full moon day starts in the south-east.
अमावास्यां वायवे च राहुर्वै तिथिरूपकः ।
The new moon day is in the north-west. Write ra on the south side and ha in the north-west.
प्रतिपदादौ ककारादीन्सकारं नैर्ऋते पुनः ।
Letters are written from ka, starting from the first moon day. Defeat comes at Rahu's mouth.
विष्टिरग्नौ पौर्णमास्यां करोलीन्द्रे तृतीयकम् ।
Vishti moves by moon day: south-east on the full moon, east on the third, south on the seventh, north on the tenth.