David set apart the sons of which three men to prophesy with lyres, harps and cymbals?

Answer: Asaph, Heman and Jeduthun

David and the army commanders set apart the sons of Asaph, Heman and Jeduthun for prophesying with music in the temple service.

“Additionally, David and the commanders of the army set apart some of the sons of Asaph, Heman, and Jeduthun to prophesy with the accompaniment of lyres, harps, and cymbals. The following is the list of the men who performed this service:”— 1 Chronicles 25:1 (BSB)