Hacham Ben Zion Abba Shaul was born in Jerusalem on 29 Tammuz 5684 (1924), the eldest of fifteen children – ten girls and five boys – born to Rabbanit Banya and Rabbi Eliyahu Abba Shaul, who immigrated from Persia. Hacham Ben Zion Abba Shaul was raised in the Shmuel HaNavi neighborhood and educated in the Bnei Zion Talmud Torah. At the age of 11 he went on to the Porat Yosef yeshiva, and studied with great rabbis – Hacham Yaakov 'Adas, Hacham Tzadka Hotzin and the Head of the yeshiva, Hacham Ezra Attiah. His study colleague was Hacham Ovadia Yosef.
When he came of age, he married Mas'ouda Shaharabani, daughter of Sol and Rabbi Yosef Shaharabani, the head of the Emet veShalom kabbalist yeshiva, and lived in Jerusalem's Beit Israel quarter. The couple had a daughter, who died as a child, and a son named Eliyahu Abba Shaul who is currently head of the Or LeZion yeshiva.
Hacham Ben Zion Abba Shaul gave classes in many places, teaching Torah scholars, adults, youths and the general populace –at the levels appropriate to each type of public. He taught halakha every Sabbath before the Minha [afternoon] prayer at the Ohel Rachel synagogue in Jerusalem for many years while he was in good health. He and Rabbi Yehuda Tzadka were jointly appointed heads of the Porat Yosef yeshiva, where he taught many students, several of whom are the leading Torah and Talmud scholars of our day. He was a mohel until the last 15 years of his life, during which when his right arm was paralyzed, and had the privilege of bringing thousands of boys into the Covenant of Abraham.
His works include a series of different books bearing the same title, Or LeZion: Responsa and Rulings, in three parts; innovations on Tractates Yevamot, Ketubot and Shevi'it, and Zichron Hadassah - a book on ethics and Hashkafa [worldview] which he named after his decease wife, Mas'ouda Hadassah Abba Shaul, may her memory be eternal.
Hacham Ben Zion Abba Shaul fell ill in 1983 and subsequently suffered greatly, even losing his sight. He passed away on 19 Tammuz, 1998, and was buried in Jerusalem's Sanhedria cemetery.