The attacker, who is understood to have been arrested, shouted the Islamic phrase meaning God is great during the attack, according to reports in French media.
The 62-year-old victim, who is described as belonging to the orthodox Hasidic sect, was injured in the attack in the Jewish Quarter, 500 metres from the Great Synagogue of Strasbourg.
Named locally as Chalom Levy, he took refuge in a nearby bar befofe being taken to hospital.
Mendel Samama, a Strasbourg rabbi who visited him at the hospital, said Mr Levy described surviving the attack as a “miracle”.
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