The Poetic Songs/Gathas of Zarathustra start with Yasna 28, with the word ahyá (self, essence.) The last word of the Gathas is vahyö, (better, more excellently.)
In the ancient Mazda Worship, ahuras are “primeval god powers” who continuously strive to better themselves. Zoroastrianism sees eternal journey towards “continuous betterment, more excellence” as the essence of Godhood, and union with the Hallowed Immortals through xratü “wisdom, creativity splendid craftsmanship/skill,) as the fundamental purpose of mortals life.
The váršt.mánsar commentary of Yasna 28 states that Zarathustra as model/source of emulation for mortals has come to the supreme heaven, the abode of songs (referring to méṇ gairæ in the Avestan original.)
In the Zoroastrian creation account, the supreme god, Ahûrá Mazdá has created the worlds by his “melodious songs, power of mind/imagination, and great music.” It shall be added that the Avestan word for “song, melodious poetry” gairæ here has Celtic “Bard” as cognate.
The váršt.mánsar commentary identifies the abode of songs with the heaven of “good, superb mind, bright ideas” of vohü man.aŋhá. It is said that in the realm of “good, wondrous mind, creative imagination” of vohü.man, the wisdom (vîduš) of all that has been done in the physical dimension as well as all that will be done, though may be hidden to us here, are readily apparent. Also, that good works have their optimal prospering (áyaptá.)
And from wondrous qualities of the supreme heaven of songs/music is the indestructibility (aγžaônvamnəm) of all those who have their genesis in good thoughts, and bright ideas. Furthermore, at the splendid, fresh, new creation of the worlds (Farš.kard,) the supreme “heaven of songs/good mind, creative imagination” descends to the star station, and the earth is lifted up there.
(The Indo-European form of Avestan aγžaônvamnəm is dhgwhei-.)
In the Avesta or the Zoroastrian sacred lore, before the supreme heaven, there are the star, moon and sun stations. These three stations respectively represent the abodes of good thoughts, inspiring words and great deeds.
The idea here is to restore paradise, supreme joy here on earth, and restore the numinous beauty and excellence that is inherent in the pristine creation.
It is this realm of good mind, superb ideas that needs to be consulted and asked always.