So he left there, before the ark of the covenant of the Lord,
 Asaph and his brethren
 Whom he, that is, David, had appointed for the service of it: 
 to minister before the ark continually;
 in singing the praises of God: 
 as every day's work required;
 at the time of the morning and evening sacrifice, as Jarchi and Kimchi interpret it.