Sefer HaYashar of Rabbeinu Tam. Krakow, 1586.

A most prominent book on ethics. This is the first edition to be printed in the Ashkenaz lands. Practices in service of G-d, ethical rebukes and topics of repentance. 

The book was attributed in error to Rabbeinu Tam Baal HaTosafot, owing to his Halachic work, Sefer HaYashar. Rabbi Avraham Seba wrote in his book, Tzror HaMor Parshat Nitzavim: They say that Rabbi Tam wrote it.

Rabbi Menachem di Lonzo writes that its author is Rabbi Zerachia HaYevani, and the Chida leans towards this opinion. (See Shem HaGedolim edited by Rabbi Zerachia HaYevoni).

Krakow, 1586.

28 leaves. Good-Very good condition. Complete.