He was 62 and was battling a rare type of malignant growth.

Born in Montreal on 8 Tishrei 5714, his father was Rabbi Heshel Ceitlin, a known Mashpia and Mohel, and his mother Rivka. He was named after his known grandfather, R' Aaron Eliezer Ceitlin who fought for Judaism in Communist Russia.

In his youth, Aaron Eliezer learned in Yeshiva Tomchei Tmimim Lubavitch of Montreal and was particularly influenced by the famed Kabbalist and Mashpia Rabbi Volf Greenglass OBM.

A letter sent by him on Adar 5731 (1971) to the Rebbe's secretariat places him in Montreal, where he was leading the "Committee of Operation Shmura Matzah." Along with Rabbi Isaac Schwei and Shmuel Glick, Rabbi Ceitlin oversaw the distribution of 390 pounds of Matzah to Jewish residents.

The following year, 5732 (1972), Rabbi Ceitlin was chosen by the Lubavitch community to receive Shmura Matzah on their behalf from the Rebbe's hands to be used at their Seder table on the first night of Pesach. Still a Yeshiva student, he represented some 80 Chabad families in this visit.

He spent the years of 1973-1975 in Australia as part of the 4th group of Talmidim Shluchim sent by the Rebbe to strengthen the Jewish community in Melbourne. While there, they also visited other cities such as Auckland, New Zealand, to evaluate the local Jewish needs.

Australian Lubavitchers --among them the families New, Gutnick and Feiglin-- were instrumental to Rabbi Ceitlin's success years later when he founded the network of Chabad Kindergartens and daycare centers around the holy city of Tzfas.

A few of the fellow student shluchim he went with to Australia continued with him for a summer mission in Los Angeles, where they learned and did outreach work out of the Chabad Russian Immigrant Program & Synagogue led by Rabbi Naftali Estulin.

During that summer they distributed large amounts of Mezuzos, Shabbos candles, charity boxes and gave shiurim at the Yeshiva Ohr Elchanan which would later be transferred to Chabad. A highlight they reported about to the Rebbe was convincing a young Jewish woman not to convert to Christianity.

He would regularly report to the Rebbe about his activities and was instructed to do so every Rosh Chodesh. Those reports were painstakingly written with deep concentration and sincerity as a chossid to his Rebbe. He once debated for 30 minutes whether he was permitted to extend a blessing to the Rebbe.

Between the years 5736-5738, Rabbi Ceitlin was one of the unique group of people who were handpicked by the Rebbe's as his personal Shluchim to the Holy Land. "The Rebbe said that our mission is to build the land materially and spiritually," Ceitlin later recalled.

Still a bochur at the time, he and the group were accompanied by 770 Rosh Yeshiva Rabbi Mordechai Mentlick. Upon arriving, they met with then-Prime Minister Yitzhak Rabin to present him 10,000 Israeli lira from the Rebbe as "symbolic participation in building the land."

In Tzfas, Rabbi Ceitlin founded and directed the Chabad Kindergarten Network with 34 branches educating some 1,500 children.

Not forgetting children enrolled in other kindergartens around Tzfas (half in the city were run by him), he would invite them to the annual pre Shavuos rally at the central Chabad shul for a memorable event that included prayer, prizes for Mitzvos and kissing the Torah.

Even after founding and managing 34 kindergartens, Rabbi Ceitlin would enthusiastically quote what the Rebbe's Chief of Staff Rabbi Mordechai Hadakov would tell veteran Shluchim, "the big buildings are only to serve the core purpose of helping another Jew do a Mitzvah."

Rabbi Ceitlin has brought scores of people from Tzfas to connect with the Rebbe in New York. For 23 years, he led an organized trip for hundreds of high school and seminary girls to New York for Chof Beis Shvat, the yartzeit of Rebbetzin Chaya Mushka Schneerson, wife of the Rebbe, and the annual convention of Chabad girls.

During those impactful trips, the young women would be privileged to speak to the Rebbe's secretaries and known chassidic scholars and strengthen their identity as chassidim.

Rabbi Ceitlin has been traveling around the world and motivating young and old in Chassidic farbrengen gatherings and personal discussions. He was a featured speaker at the International Convention of Chabad Shluchim in New York, the Convention of Directors of Chabad Centers in Israel, Conference of Chabad Educators in Israel, Evening of Chabad Activists in Israel and at many communities, Yeshivos and educational institutions.

The words of Rabbi Ceitlin, following the terror Mumbai attacks, "We don't understand G-d, we can't answer G-d. We are 100 percent sure that every pain that G-d does is only a preparation for much greater goodness that will be revealed very soon. We have to go on stronger and stronger, add in light and spreading the Torah," gave many strength in face of challenges.

He is survived by his wife Mrs. Ruti Ceitlin, their children Rabbi Levi Ceitlin - Krayot, Israel; Chanie Ceitlin - Tzfas; Rabbi Mendy Ceitlin - Tzfas; Devorah Leah Edelkopf - US; Sterna Edelkopf - Crown Heights; Chaya Wolosow - Tzfas; Heshy Ceitlin; and grandchildren.

He is also surived by his mother Mrs. Riva Ceitlin - Montreal, Canada; siblings, Mrs. Sterna Kalmenson - Ohio; Bracha Teitelbaum - Crown Heights; Zelda Yarmush - Montreal, Esti Benshimon - Montreal; Rabbi Yosef Yitzchok Ceitlin - Toronto, Canada, Devora Leah Mishulovin - Los Angeles.

The levaya will take place today, Thursday, leaving Shomrei Hadas in Boro Park at 3:00 pm and passing by 770 at 3:45 pm.

Baruch Dayan Haemes.