||Kav ha-Yashar holds the torments of hell over the heads of those who do not mend their ways and fulfill God's commandments. The book is replete with wondrous tales depicting the punishment of the evil and the reward of the righteous. The book reflects the suffering and persecution of European Jewry, and the despair wrought by the Shabbatean disillusionment. It also reveals aspects of the communal life of this time - the economic struggle, oppression by leaders of the community, and disregard of religious rituals by Jewish tax collectors whose business brought them into contact with Christian government officials and noblemen. His engaging style, which made the Kav ha-Yashar popular with the masses, and rapidly gained a reputation for it among European Jewry. It has been frequently reprinted (see Friedberg, Eked, 3, 882). R. Koidonover prepared a popular Yiddish translation (Frankfort, 1709), and a Ladino translation appeared in Constantinople (1724).
R. Zvi Hirsch Koidonover (d. 1712), rabbi and ethical writer (his name derived from Koidanovo, a town near Minsk). Koidonover was born in Vilna and spent his childhood in Kurow near Lublin until 1658 when his father's house was pillaged and his two sisters killed. The rest of the family escaped to Austria, and subsequently settled in Nikolsburg, where his father, Aaron Samuel, was appointed rabbi. Koidonover received his religious education from his father and from R. Joseph b. Judah, rabbi of Minsk and Dubnow, author of the moralistic treatise, Yesod Yosef.