The Gathas (Avestan: Gāθās) are 17 hymns believed to have been composed by Zarathusthra (Zoroaster) himself. They are the most sacred texts of the Zoroastrian faith.
The Gathas are in verse, metrical in the nature of ancient Iranian religious poetry, which is extremely terse, and in which grammatical constructs are an exception.
The 17 hymns of the Gathas consist of 238 verses, of about 1300 lines or 6000 words in total. They were later incorporated into the 72-chapter Yasna(chapter: ha or had, from the Avestan ha’iti, ‘cut’), which in turn is the primary liturgical collection of texts within the greater compendium of the Avesta.