Rabbi Kahaneman was born 13 May 1886 in Kul, Kovno Governorate of the Russian Empire, a small town of about 300 of which about a third were Jews. As a young boy he attended the Yeshivah in Plunge led by Rabbi Chaim Yitzchak Hacohen Bloch, who is credited with cultivating Rabbi Kahaneman's potential. At the age of 14 he went to study Talmud at the Telshe yeshiva, where he studied Torah until he was twenty, under the tutelage of Rabbi Eliezer Gordon and Rabbi Shimon Shkop. He then spent a half year in Novardok yeshiva, after which he spent three years in Raduń Yeshiva studying under the Chofetz Chaim and Rabbi Naftoli Trop. He married the daughter of the rabbi of Vidzh, and became rabbi there at the end of 1911, when his father-in-law became the rabbi of Vilkomir. With the passing of Rabbi Yitzhak Yaakov Rabinovich in 1919, Kahaneman was appointed the new rabbi of Ponevezh, one of the largest centers of Jewish life in Lithuania. There, he built three yeshivas as well as a school and an orphanage. All of his institutions were destroyed and many of his students and family were killed during World War II. He was elected to the Lithuanian parliament. He was also a member of autonomous National Council of Lithuanian Jewry and active member and leader of Agudat Yisrael. The outbreak of World War II caught him during his visit in the British Mandate of Palestine, after which he was intending to visit United States. Learning about Red Army occupation of Lithuania, he decided to stay in Palestine. He continued overseeing Panevezh Yeshiva from distance. After the entrance of Nazis to Ponevezh the yeshiva was destroyed and all students murdered. A few years later, in 1944, Kahaneman succeeded in re-establishing Ponevezh Yeshiva in Bnei Brak. After un-successful attempts to save European Jews, Kahaneman focused on developing communities in Palestine and built Kiryat Ha-Yeshiva in Bnei Brak and Batei Avot orphanages. He also traveled widely in the diaspora to secure financial support for the yeshiva, which he constantly improved and extended. With the help of long time friend Rav Moshe Okun, Kahaneman succeeded in turning the re-established Ponevezh yeshiva into one of the largest in the world and leading among the Litvishe. He sought to take care of many orphans, especially the Yaldei Tehran – children who escaped from Nazi Europe by walking across Europe to Tehran and other refugees, among them BialaRebbe – Rabbi Ben Zion Rabinowitz. He referred to his numerous activities as doing them with "21 fingers" - his fingers of hands, feet and finger of God. Kahaneman died on 3 September 1969 in Bnei Brak, Israel. After his death the Ponevezh Yeshiva community divided into two over the conflict on leadership. Kahaneman wrote Talmudic commentaries and an exegesis on the Passover Haggadah, nevertheless their publication -together with transcripts of his lessons - took place only after his death.
In contrast to the prevalent Haredi opposition to Zionism, Rabbi Kahaneman showed some signs of support for the State of Israel. He found the religious importance of establishment of State of Israel after the experience of Holocaust. He believed it was the plan of God. He is known for insisting that the flag of Israel be flown outside of the Ponevezh Yeshiva on Israel's Independence Day. He also refrained from saying the Tachanun prayer, a daily prayer of penitence, on that day as a sign of celebration. He was also approached - among a few others - by David Ben-Gurion, Israeli Prime Minister - to help answering the question on definition of Jew for the State of Israel. In his reply Kahaneman wrote: "I see the vision of the return to Zion in our generation as the revelation of the light of divine providence, which strengthens our hand and accompanies us through the evil waters that have risen against us … I see miracles every moment, every hour! I am sure that His Honor sees the thing as I do, for who like the ship's captain standing at the wheel of the ship sees these miracles." Following Israel's military successes of the Six Day War, he published an article in which he praised the recent successes as "obvious miracles, and even a blind person can sense the palpable miracles... the miracles, wonders, salvations, comforts and battles" and called upon recognition them as such and observing the "wondrous period".
