Mithra (Avestan: 𐬨𐬌𐬚𐬭𐬀 Miθra; Old Persian: 𐎷𐎰𐎼 Miθraʰ‍) is an ancient Iranian deity (yazata) of covenants, light, oaths, justice, the Sun,[1] contracts, and friendship.

[2] In addition to being the divinity of contracts, Mithra is also a judicial figure, an all-seeing protector of Truth (Asha), and the guardian of cattle, the harvest, and the Waters.

Thus, etymologically mitra/miθra means "that which causes binding", preserved in the Avestan word for "Covenant, Contract, Oath".

Should the Good Thoughts, Words, and Deeds outweigh the Bad, Sraosha alone conveys the Soul across the Bridge.

However, "no satisfactory evidence has yet been adduced to show that, before Zoroaster, the concept of a supreme god existed among the Iranians, or that among them Mithra – or any other divinity – ever enjoyed a separate cult of his or her own outside either their ancient or their Zoroastrian pantheons.

[5] The Khorda Avesta (Book of Common Prayer) also refer to Mithra in the Litany to the Sun, "Homage to Mithra of Wide Cattle Pastures," (Khwarshed Niyayesh 5),[6] "Whose Word is True, who is of the Assembly, Who has a Thousand Ears, the Well-Shaped One, Who has Ten Thousand Eyes, the Exalted One, Who has Wide Knowledge, the Helpful One, Who Sleeps Not, the Ever Wakeful.

The Iranian civil calendar of 1925 adopted Zoroastrian month-names, and as such also has the seventh month of the year named "Mihr".

[8] Royal names incorporating Mithra's (e.g., "Mithradates") appear in the dynasties of Parthia, Armenia, and in Anatolia, in Pontus and Cappadocia.

The second figure mentioned above, the Third Messenger, was the helper and redeemer of mankind, and identified with another Zoroastrian divinity, Narisaf (derived from Pahlavi Narsēh from Avestan Nairyō.saȵhō, meaning 'Potent Utterance', the name of a Yazata).

[9] Citing Boyce,[10] Sundermann remarks, "It was among the Parthian Manicheans that Mithra as a Sun God surpassed the importance of Narisaf as the common Iranian image of the Third Messenger; among the Parthians the dominance of Mithra was such that his identification with the Third Messenger led to cultic emphasis on the Mithraic traits in the Manichaean God.