David and the leaders of the army separated Asaph’s sons for special service. Asaph’s sons were Heman and Jeduthun. Their special service was to prophesy {\cf2\super [270]} God’s message by using harps, {\cf2\super [271]} lyres, {\cf2\super [272]} and cymbals. {\cf2\super [273]} Here is a list of the men that served this way: