Chapter 1, Mishna 1:
Moshe received the Torah from Sinai and passed it on to Yehoshua; Yehoshua to the Elders; the Elders to the Prophets; and the Prophets passed it on to the Men of the Great Assembly. They [the Men of the Great Assembly] said three things: Be deliberate in judgment; raise up many disciples; and make a fence around the Torah.
