Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 2 · War Astrology: Yogas, Nakshatras
युद्धजयार्णवः (योगाः नक्षत्राणि)
ए शान्तिर्वार्युपस्पर्शो यश्चोदानश्चला क्रिया ।ओंकारः शान्त्यतीताख्यः खशब्दयूथपालिनः ॥ १३ ॥
In the full Agni Purana this is chapter 124, verse 13.
E has the part called Peace, air, touch, the seed letter ya, Udana and Kriya, the moving power. Om is called Beyond Peace. It has space and sound, guarding the groups.
Simple meaning: 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.
एतन्मूलमतः सर्वं ज्ञायते सचराचरम् ।
From this root all is known. Next the seat of knowledge is told, and Om is called Shiva.
उमा सोमः स्वयं शक्तिर्वामा ज्येष्ठा च रौद्र्यपि ।
Several goddesses and Brahma, Vishnu and Rudra are named, with the three qualities starting with creation.