Avot of Rabbi Natan, also known as Avot de-Rabbi Nathan (ARN) (Jewish Babylonian Aramaic: אבות דרבי נתן), the first and longest of the minor tractates of the Talmud, is a Jewish aggadic work probably compiled in the Geonic era (c. 700–900 CE). It is a commentary on an early version of the Mishnah and exists in two forms: a standard printed edition and a second edition with 48 chapters published by Solomon Schechter, who labeled the two forms as A and B, respectively.
Despite being one of the minor tractates, it more closely resembles a late midrash. It may be technically designated as a homiletical exposition of the Mishnaic tractate Pirkei Avot (often abbreviated as Avot), having an older recension of that tractate for its foundation. It may also be considered as a kind of tosefta or gemarah of Mishna Avot, which does not possess a traditional gemarah.
ARN contains many teachings, proverbs, and incidents not found elsewhere in the early Rabbinic literature. Other Rabbinic sayings appear in a more informal style than what is found in Pirkei Avot.