Letter from the Netziv of Volozhin to his son Rabbi Chaim Berlin. Torah thoughts and polemic

Letter from the Netziv of Volozhin to his son Rabbi Chaim Berlin. Torah thoughts and polemic
Lengthy letter from Rabbi Naftali Zvi Yehudah Berlin [the Netziv] to his son Rabbi Chaim Berlin. 
[1] leaf, 21x26 cm. Written in the Netziv's handwriting, with his signature.
Lengthy letter of Torah thoughts. The Netziv opens with the words: "Now I relate Torah thoughts in short." The letter relates to two sugyot in Tracate Pesachim. The two passages were later printed in the Netziv's works Meromei Sadeh on Tractate Pesachim and Shu"t Meishiv Davar (section five).
In the margins, the Netziv writes to his son about a kuntres that someone wrote and signed with forged signatures and was then publicly embarrassed. "Someone who wants to lie should go where people won't recognize his deeds." Perhaps this relates to the polemic regarding Shemittah about which the Netziv wrote the Dvar Shemittah booklet (printed in Meishiv Davar).
Rabbi Naftali Zvi Yehudah Berlin - the Netziv (1816-1893), was the head of the renowned Volozhin yeshiva for 40 years. He was one of the most noted Torah scholars in Eastern Europe. He authored the HaEmek Sheilah, HaEmek Davar, Shu"t Meishiv Davar, and more. His son, Rabbi Chaim Berlin (1832-1913), was rabbi in Moscow and Rosh Yeshiva of Volozhin for a short period of time. He then served as rabbi of Kobrin before moving to Jerusalem.
Professional repair to light marginal tears, affecting two words. Aging stains. Fine condition.