Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · War Astrology: Yogas, Nakshatras
युद्धजयार्णवः (योगाः नक्षत्राणि)
वक्ष्ये जयशुभाद्यर्थं सारं युद्धजयार्णवे ।अ इ उ ए ओ स्वराः स्युः क्रमान्नन्दादिका तिथिः ॥ १ ॥
In the full Agni Purana this is chapter 123, verse 1.
I will tell the essence of victory and good results from the Yuddhajayarnava. The vowels a, i, u, e, o come in order. The tithi (moon days) beginning with Nanda go with them in order.
Simple meaning: The five vowels are matched in order with the five groups of moon days.
कादिहान्ता भौमरवी ज्ञसोमौ गुरुभार्गवौ ।
The consonants are shared among the planets. Mars, the Sun and Saturn go with the right breath.
खार्णवः खरसैर्गुण्यो रुद्रैर्भागं समाहरेत् ।
This is a counting rule: multiply, divide, multiply again, then divide by the earlier part.
वह्निभिश्चाऽऽहतं कृत्वा रूपं तत्रैव निक्षिपेत् ।
Multiply by 3 and add 1. This counts the throbs of the breath and the small time units.