Jamieson, Fausset & Brown

the veil is--rather, "a veil lieth upon their heart" (their understanding, affected by the corrupt will, Joh 8:43; Co1 2:14). The Tallith was worn in the synagogue by every worshipper, and to this veil hanging over the breast there may be an indirect allusion here (see on Co1 11:4): the apostle making it symbolize the spiritual veil on their heart.