"You did disgusting things ... you have the nerve to even walk around in public," the man tells Weiner.
"Oh, yeah? And you're a perfect person? You're my judge?" Weiner responds. "What rabbi taught you that?"
In another video, released by the Weiner campaign later Wednesday, the man can be heard saying "married to an Arab," presumably a reference to Weiner's Muslim wife, Huma Abedin, a longtime aide to former U.S. secretary of state Hillary Rodham Clinton.
Weiner, once a front-runner among the Democratic candidates for mayor, was in the neighborhood greeting voters ahead of the Sept. 10 primary. Support for his campaign has collapsed amid a new sexting scandal similar to the one that forced him to resign from Congress. Polls show Weiner is now a distant fourth among the Democratic candidates seeking to replace independent Mayor Michael Bloomberg, who's serving the last of three consecutive terms.
Weiner, who's Jewish, was buying sweet cake at the bakery ahead of the Jewish New Year, Rosh Hashana, which began Wednesday at sundown.
Weiner defended his behavior outside a campaign stop at a Manhattan senior citizens center after the 2-minute video gained attention online, saying he put the man in his place.
"He was saying things within my earshot but not to me and saying some pretty vile things, and apparently he didn't expect that I would not stand idly by for it, and I think I put him in his place," Weiner told reporters. "Just because someone is running for office doesn't mean you have an unabridged right to say whatever vile, nasty thing you want."