continually morning and evening - as the law enjoined (Exo 29:38; Num 28:3, Num 28:6).
and do according to all that is written in the law - (See Num 28:1-31). Thus, in the time of David, the worship was performed at two places, where the sacred things that had been transmitted from the age of Moses were preserved. Before the Ark in Jerusalem, Asaph and his brethren officiated as singers, Obed-edom and Hosah served as doorkeepers, and Benaiah and Jahaziel blew the trumpets. While at the tabernacle and burnt offering in Gibeon, Heman and Jeduthun presided over the sacred music, the sons of Jeduthun were door keepers, and Zadok, with his suite of attendant priests, offered the sacrifices.