Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · War Astrology: Yogas, Nakshatras
युद्धजयार्णवः (योगाः नक्षत्राणि)
आर्द्रा हस्तस्तथाऽऽषाढाचतुष्कं चोत्तरात्रिकम् ।(मध्ये स्तम्भचतुष्कं तु दद्यात्कोटस्य कोटरे
In the full Agni Purana this is chapter 128, verse 9.
Ardra, Hasta, Ashadha and an Uttara make a group of four. Put this group of four pillars in the middle, in the hollow of the Kota. (Our text is unclear here: the words naming the Ashadha and the Uttara.)
Simple meaning: Ardra, Hasta, Ashadha and an Uttara are the four pillars in the centre of the fort.
एवं दुर्गस्य विन्यासं बाह्ये स्थानं दिशाधिपात्।) आगन्तुको यदा योद्धा ऋक्षवान्स्यात्फलान्वितः
The fort figure is complete. A fighter coming from outside succeeds if he has the right nakshatra.
कोटमध्ये ग्रहाः सौम्या यदा ऋक्षान्विताः पुनः ।
With good planets and nakshatras in the middle, those inside win. The one who comes from outside is beaten.
प्रवेशभे प्रवेष्टव्यं निर्गमभे च निर्गमे(च्छे)त् ।
Enter the fort in the entering nakshatra, and leave in the leaving one. Venus, Mercury and Mars matter here.