Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · War Astrology: Yogas, Nakshatras
युद्धजयार्णवः (योगाः नक्षत्राणि)
गन्धो न बीजः प्राणाख्य इडा शक्तिः स्थिरा स्मृता ।इकारश्च प्रतिष्ठाख्यो रसोयानश्च पिङ्गला ॥
In the full Agni Purana this is chapter 124, verse 11.
For a: smell, the seed letter na, the breath called Prana, Ida (breath through the left nostril), and the steady power. The letter i is called Pratishtha. It has taste, the Apana breath, and Pingala (breath through the right nostril).
Simple meaning: The vowels a and i are matched with senses, seed letters, breaths, and the left and right breath.
क्रूरा शक्तिरीबीजः स्याद्धरवीजोऽग्निरूपवान् ।
Powers and seed letters are named, including cruel Shakti and a fire-like seed.
ए शान्तिर्वार्युपस्पर्शो यश्चोदानश्चला क्रिया ।
The vowel e goes with air and touch. Om goes with space and sound.
पञ्च वर्गाः स्वरा जाताः कुजज्ञगुरुभार्गवाः ।
The five letter groups come from the vowels and match Mars, Mercury, Jupiter, Venus and Saturn in order.