That pledge was recalled last week, according to Chabad.org, when at a gathering of 500 Jewish leaders and ambassadors including India's Ambassador Meera Shankar, it was announced that Rabbi Chanochm, 25, and Leiky Gechtman, 23, will return to Mumbai as the first permanent Chabad-Lubavitch emissaries since the attacks.
The Chabad-Lubavitch movement, which started in Russia over 220 years ago, seeks to revive the Jewish faith, and advocates a simple and devotional life. It believes Israel should not make any territorial concessions to the Palestinians.
The Grechtmans will not only run Chabad House, which welcomes Jews traveling through India, but will also invite the few thousand strong Mumbai Jewish community to prayers, reading the Torah and socialise with them and others. The movement welcomes Jews of various theological persuasions.
The Mumbai Chabad centre is one of the 3,300 Chabad institutions in more than 950 cities in at least 75 countries. Though the movement based in Brooklyn has about 200,000 adherents, it draws thousands to their services, schools and camps.
"Rabbi Gavriel and his wife Rivka are, of course, irreplaceable," Rabbi Moshe Kotlarsky, vice-chairman of the educational arm of Chabad-Lubavitch, said last week.
"But now, there is a rabbi who will go there in a few weeks to continue their work and revive Chabad activities in Mumbai."
A key factor in choosing the Grechtmans was the endorsement they received from Rabbi Holtzberg's father Rabbi Nachman Holtzberg.
Rabbi Yosef C Kantor said the Gechtmans are a perfect fit as "Gabi liked him and relied on him, and for good reason. He is a wonderful young rabbi. He is personable, enthusiastic, organised and dedicated."
Gechtman first went to Mumbai in 2006 to assist the Holtzbergs after the birth of their son Moshe, who survived the attack. Gechtman, who studied rabbinical law under Gavriel Holtzberg, stayed in the city for five months, spending most of his free time teaching the Torah one-on-one with the Israeli backpackers who came in and out of the centre, Cantor recalled.
He wasn't keen on returning to India, but eventually decided to go there wholeheartedly because of his love for the slain couple. He was not looking for another position, he said, adding that his wife and him were working in Israel, where his in-laws have a busy Chabad centre.
Leah Gechtman, a rabbi's daughter, at first said she wouldn't hear of returning to India. "But then it occurred to me that if the Rebbe (the supreme leader of the movement, Menachem Mendel Schneerson, who died 16 years ago) were alive and would ask us to take the assignment, we would be honoured," she added. 'That changed my way of looking at it, and I began to consider it.'
The Gechtmans were in Israel when Mumbai was attacked. They are still trying to come in terms with the murder of their friends.
"I still haven't processed that they are not here," Gechtman mused, adding that he considered the slain emissaries as role models.
"The reality doesn't fit," he explained. "I can't fathom that they are not alive; sometimes, it seems like they are people who live forever, that something like this can't happen to them."