"Yasht" 13 is one of the eight "great" "yashts", and at 158 verses the longest text in the collection, and one of the better preserved ones as well. It is also the second-most frequently recited "Yasht" (after "Yasht" 1 to Mazda). Several different authors contributed to the hymn, and its literary quality is uneven; while some verses are rich in traditional poetic phrases, others are of dully imitative prose. The frequently repeated "kshnuman" (formulaic invocation) of "Yasht" 13 is "We worship the good, strong, bounteous fravašis of the righteous (ashavan)."