What do we learn from "ha'Lo Kasavti Lech Shalishim [b'Mo'etzos va'Da'as]"?
Megilah 7a: Esther asked Chachamim to make Megilas Esther part of Kesuvim. They refused - "I have written [about war with Amalek] three times" (in Shemos, Devarim and Sefer Shmuel. It should not be written a fourth time 1 !)
Rashi: This refers to Torah, Nevi'im and Kesuvim.
R. Yonah: It is a metaphor that encompasses the matter and rules over it. This is like an officer who rules over a number of people under his authority This is like "Shim'u Ki Negidim Adaber" (8:6).
Malbim: This is like "Va'Ydaber Sheloshes Alafim Mashal" (Melachim I, 5:12). Sefer Mishlei is divided into three parts. Shalishim b'Mo'etzos - all three are full of Etzos (counsels) how to conduct. V'Da'as - so you will have a clear knowledge to teach others.
7a: Later, they consented due to "write this as a remembrance in a Safer." "Write this" refers to Milchemes Amalek in Shemos and Devarim; "a remembrance" is in Shmuel, and