Mordechai was born in 1930, in Jerusalem’s Nahalat Zion neighborhood to his father, Yaakov Abud Levi, one of the neighborhood’s protectors, and his mother, Rachel Ajami, of Jerusalem. He was an only child, raised by his grandmother. His father was a stonemason who worked as a special policeman. He studied in cheder and started working at a very young age.
At age fifteen, he joined Lehi. Like other youths, his first work in the underground was putting up posters. After he underwent firearms training, he was put in the combat unit. His first operation was confiscating four Tommy guns by threatening British policemen on King George Street. Another activity in which he took a central part was liberating a dozen Lehi and IZL prisoners from the Jerusalem Central Prison. In this operation, three underground members, including Mordechai, were disguised as public works department employees. The prisoners had dug a tunnel from their cells to the sewage lines, and they helped them escape. Mordechai picked up the manhole cover and warned Matityahu Shmuelevitz, first of the escapees, about the British officer who was watching the site. He entered the sewer, gave his department of public works uniform to the escapee, and the latter managed to escape without arousing suspicion. After this, another eleven escapees were liberated.
The British arrested Mordechai and even imprisoned him in Latrun, but they released him after a few days because he was so young. Shortly before the British left, Mordechai attacked Arab targets, blowing up, among other places, houses which Arab snipers had used in Katamon and Malha. His back was injured in one of these operations.
Despite his disability, he enlisted in the IDF in 1951, serving among other places in a police uniform in the Mt. Scopus enclave. After a year, he was discharged as medically unfit; however after a petition to the High Court of Justice, he was recognized as an IDF disabled person. After his discharge, he worked for the Municipality of Jerusalem, and after two decades, he retired early due to his medical condition.
In 1954, he married Yaffa Levi. They had three sons, three daughters, and numerous grandchildren. One of his sons was named Dror, a Lehi member who fell at Sheikh Badr; one of his daughters was named Ofra, after the Lehi member who recruited him.