|This article may not meet the general notability guideline. Please help to establish notability by adding reliable, secondary sources about the topic. If notability cannot be established, the article is likely to be merged, redirected, or deleted. (September 2009)|
|This article relies largely or entirely upon a single source. Please help improve this article by introducing appropriate citations of additional sources. (September 2009)|
Orphaned as a child, he was raised by his uncle Rabbi Nochum, who sent him to be educated in one of the highly acclaimed yeshivot in Lithuania. After his marriage he earned his livelihood as a teacher of young boys, while continuing his intensive studies of Torah.
With the advent of Chassidism, Rabbi Nochum became a disciple of the Baal Shem Tov, the founder of Hasidism. After the Baal Shem Tov's passing, R' Nochum accepted the Maggid of Mezritch as his mentor. His book Me'or Einayim (Light of the Eyes) was published later in his life, and contains a collection of his teachings on the weekly Torah portions and selections of the Talmud. The book gained widespread acceptance as one of the major works of Hasidic thought.
He was succeeded as the Maggid of Chernobyl by his son Rabbi Mordechai Twerski. The surname would become known as Twersky in the United States. The Chernobyl dynasty branched into a number of successive dynasties through Mordechai's eight sons, including those of Skver, Rachmastrivka, Trisk, and Tolna.
Menachem Nochum was once approached by a distinguished-looking person who offered to teach him secrets of the Torah. Reb Nochum said, "I cannot accept your offer until I consult with my Rebbe." When he sought his Rebbe's advice, the Mezritcher Maggid replied, "It is good that you came to ask, because that person was a representative of the spiritual forces which oppose holiness." "Incidentally", the Rebbe asked his disciple, "What gave you the idea of inquiring before accepting his suggestion?" Reb Nochum answered, "When I was young, my mother died and my father remarried. My stepmother was very cruel to me. I once came home from yeshiva for lunch when she was not home and noticed that she had left some fried eggs on the stove. Not wanting to waste time, I decided to serve myself and took a portion smaller than what she would normally give me. She returned home while I was eating and abruptly struck me across the face. I began to cry, and pleaded with her, 'Why did you hit me? I took less than what I normally receive!' She replied, 'I am punishing you because alain nemt men nit — One should not take anything alone without permission.' Since that very day I learned not to take anything without permission, regardless of how good or desirable it may be."