BOROUGH PARK, Brooklyn (WPIX) -- Amid the fog of international travel, a group of Jewish students studying in Jerusalem was handed a backpack -- that none recognized as their own. Fortunately for the rightful owner, these students believe in doing good deeds, or mitzvahs, as part of their daily l ives. After returning home for the Jewish holidays, a Brooklyn, New York, exchange student — who prefers to remain anonymous — never expected a lost bag, and the attention that followed, to land in his lap at Newark Airport. Sand cat at Greensboro Science Center advances to final round of nationwide photo competition A cab driver had mistakenly handed over the backpack while unloading the student’s luggage. "The yellow cab comes back, opens the window, says, ‘Someone left this,’ hands it over to me, and drives away," the student, 20, recalled. Before he could tell the driver it wasn’t his, the cab had already sped off. The student was stunned when he opened the bag in an attempt to find its rightful owner. "First, I saw a laptop," he said. "Then I started opening other areas and seeing jewelry." "I was shocked," he added. "It looked like expensive stuff." Inside the bag, he found a custom diamond-encrusted pendant, Rolex watches, loose diamonds, other jewelry, and cash — with an estimated value over $100,000. He immediately told his mother, who advised him to call Shmira, a Brooklyn public safety group. Shmira volunteers took the backpack and began investigating. "This is what we do," said Levi Leifer, director of the Shmira chapter. "This is our mission, our 24/7." Fortunately for the rightful owner, these students believe in doing good deeds, or mitzvahs, as part of their daily lives. (Credit: Shmira Public Safety) The group eventually found a phone number linking them to the bag’s owner, who told Nexstar's WPIX that he works in New York City’s Diamond District but would not provide any additional information.  "Was he a distributor? A wholesaler? A customer? I’m sure, with time, we’ll get more clarity on the story itself," Leifer said. Winston-Salem State University reaches historic milestone with largest graduate student enrollment After confirming ownership, Shmira invited the ecstatic man to their Borough Park office. "While he's talking, we see fear, assuming the bag is empty," Leifer said. "But when he opened it, he couldn’t believe it. You had to see his eyes." "He was very, very excited, looked very happy." Blown away by the students’ honesty, the owner offered a reward, which they declined. ...read more read less