Avraham was born on 20.9.1933 in Pazardzhik, Bulgaria, to Esther and David Rosen. His family was Zionist and traditional. His father was active in the Revisionist Party. When Bulgaria aligned with the Axis powers in World War II, his family left and made aliyah in 1942, settling in Petah Tikva.
Avraham studied in Netzach Israel Elementary School. After some time, he completed his high school studies at night and in the ORT Professional School. He also studied at a school in Petah Tikva for botany, gardening and technology.
He was recruited to Lehi in the mid-1940s by Hayim Amsterdam (Sagiv), whose nom de guerre was Yirmeyahu, once Avraham assured him that he was far more mature than his age might indicate.
Like other youths, he put up posters and distributed materials. One night when he was putting up posters with two others, they were seized by British soldiers, who put them on a truck. However, before they could close the door, one of the boys threw the pail of hot glue at the soldiers, which allowed the three of them to jump off the truck and run away.
Once the State was established, he moved on to the Lehi base at Sheikh Munis, and once the adult members of Lehi had joined the IDF on 29.5.1948, he moved on to Lehi’s Camp Eldad in Jerusalem. In 1951, he enlisted in the IDF, serving as a sergeant in the Golani Brigade, and later in the Artillery Corps. He was discharged in 1954. He fought in the Sinai War and in the Yom Kippur War.
In 1959, he married Dalia Yaakov. They had five daughters. He worked as a landscaper, and he was an expert in tropical plants. He worked in the Botanical Department of Tel Aviv University, and he was the technical director of botanical gardens. He now spends his time on his hobbies: painting, sculpting, metalwork and playing the guitar.