Mithra as described in this Yasht, guardian of contracts and covenants who cannot be deceived and who observes from the light before sunrise whether agreements between people are honored, is the Zoroastrian development of a figure attested even earlier in the wider Indo Iranian religious world, related to the Vedic Mitra recorded independently in the Rig Veda, evidence the god predates Zoroastrianism itself and was absorbed into the developing Zoroastrian system rather than originating within it. Centuries later and in an entirely different empire, a god called Mithras became the object of a popular mystery cult across the Roman world, especially within the Roman army, from roughly the first to the fourth centuries CE, complete with its own initiatory grades, underground temples called mithraea, and iconography, most famously depicting Mithras slaying a bull, that has no clear counterpart in the Zoroastrian material at all.
How much genuine continuity connects the Avestan Mithra of this Yasht to the Roman Mithras of the mystery cult is a long running and unresolved scholarly debate. The early twentieth century historian Franz Cumont argued for substantial continuity, treating Roman Mithraism as a transplanted and adapted Persian religion. Later scholars, including Roger Beck among others, have argued the Roman cult was largely a new Roman creation that borrowed the name and some Persian trappings for exotic prestige while inventing much of its actual theology and central bull slaying iconography independently, with little direct doctrinal continuity from the Avestan material. The debate remains open, and this Yasht is frequently cited by both sides despite supporting neither conclusively on its own.