When David is introduced in Scripture, he has a shepherd’s rod and staff (1 Samuel 16:11). In the next scene of his life that the Scriptures record, David has a harp (1 Samuel 16:23). One of King Saul’s servants described him as one “who is skillful in playing, a mighty man of valor, a man of war, prudent in speech, and a handsome person; and the Lord is with him” (1 Samuel 16:18). What an accurate thumbnail sketch!
Because David lived and died under the Law of Moses, his harp was authorized in the worship of Jehovah. Second Chronicles 29:25 clearly states that King Hezekiah “stationed the Levites in the house of the Lord with cymbals, with stringed instruments, and with harps, according to the commandment of David, of Gad the king’s seer, and of Nathan the prophet; for thus was the commandment of the Lord by His prophets.” It is significant to note that it was by the mouth of three different witnesses that God plainly commanded (and thus expected) the worship of David to include his voice and his harp. Therefore, David writes, “I will sing a new song to You, O God; on a harp of ten strings I will sing praises to You” (Psalm 144:9).
When Jesus died, the Law of Moses ended (Romans 7:1-4; Ephesians 2:14-16; Colossians 2:13-14). Its duration was from Mount Sinai to Mount Calvary. With His death, Jesus’ new testament went into effect (Hebrews 9:16-17). His blood shed at Calvary inaugurated the new covenant (Luke 22:20) prophesied by Jeremiah (Hebrews 8:8-13; Jeremiah 31:31-34).
While there are some similarities between the old covenant (which David lived under) and the new covenant (which we live under), there is a host of differences—no animal sacrifices, no annual feasts in Jerusalem, no Sabbath worship, no required circumcision of males on the eighth day, etc.
Another difference is in the music offered in praise to God. David praised God using his voice and his hands. You and I are to praise God using our voices and our hearts; we are to be “singing and making melody in your heart to the Lord” (Ephesians 5:19) when we worship.
Ask any schoolboy, and he can show you the difference between your hands and your heart whenever he says the Pledge of Allegiance to the flag.