During the blessing that originated with the giving of the Torah at Mount Sinai, the Kohanim - the priestly class - bless the Jewish nation twice, once during the Shaharit service and once during the Musaf service. The ceremony ends with a reception for the chief rabbis, who conducts the blessing. The tradition for hundreds of priests from around the world to gather at the Western Wall, and recite the ancient blessing during Hol Hamoed, has been observed for the past 40 years. During the Priestly Blessing in October 2009 massive rioting broke out on the Temple Mount and throughout east Jerusalem, following rumors circulated by Muslim priests that spoke of a "Jewish plot" to take over the incendiary holy site.