The Mishnah or Misnah (“study, repetition”) is the first major written collection of Jewish oral traditions known as the Oral Torah. It is also the first significant work of rabbinic literature. The Mishnah was compiled by Yehudah Hanasi in the early 3rd century CE, at a time when, according to the Talmud, Jewish persecution and the passage of time posed the risk of forgetting the details of the oral traditions of the Pharisees from the period of the Second Temple (536 BCE-70 CE). Most of the Mishnah is written in Mishnaic Hebrew, while some parts are in Aramaic.
Source: Shiva Shambho
Books on the Mishnah