Born in Poland, Rabbi Weinbach was raised in Pennsylvania, and went to study in New York, earning his rabbinical ordination at Yeshiva Torah Vodaath in Brooklyn. He married Sylvie (Sheindel) Lamm, a Belgian war orphan who came to New York at the age of 5. She and her parents, Abraham Israel and Rachel Lamm, had been interned in the Mechelen transit camp in 1942. She had been liberated on 13 January 1944 and sent to a Jewish orphanage; her parents were tragically deported to Auschwitz two days later. Raised by her aunt and uncle in New York City, Lamm married the promising young talmid chacham, and ultimately moved with him to Kiryat Mattersdorf in northern Jerusalem, where they raised their 12 children.
The 1960s and 1970s were a time of searching for meaning by Western-educated, college-age men and women. In 1970, Rabbis Noach Weinberg, Mendel Weinbach, Nota Schiller, and Yaakov Rosenberg founded Shema Yisrael Yeshiva to attract young Jewish men with little or no background in Jewish studies. After a few years, Weinberg left the yeshiva over a difference in philosophy and founded Aish HaTorah in 1974. Shema Yisrael subsequently changed its name to Ohr Somayach, after the commentary on the Mishneh Torah written by Rabbi Meir Simcha of Dvinsk, the Ohr Somayach, in response to critics who contended that the phrase “Shema Yisrael” belonged to the entire Jewish people, not just one institution.]
Among the many religious works authored by Rabbi Weinbach were such popular titles as The Weekly Daf, a compendium of commentary on the Talmud; The Essential Malbim: Flashes of Insight on Bereishis/Genesis; The Essential Malbim: Flashes of insight on Shemos/Exodus; the two-volume Give Us Life: Mesholim and masterwords of the Chofetz Chaim; 127 Insights Into Megillas Esther; the Lifeline Series (3 volumes); Love of the Land; On Wings of Prayer: Mesholim and Illuminations on the Daily Prayers by the Chofetz Chaim and Other Torah Greats; and TalmuDigest.
Rabbi Weinbach was buried on Har Hamenuchos in Jerusalem.