David appears to be an older teenager (or in his early 20s). He is standing against a draped background in front of King Saul, who is seated. David is playing a musical instrument and singing.
14 Now the Spirit of the LORD departed from Saul, and a harmful spirit from the LORD tormented him.15 And Saul's servants said to him, “Behold now, a harmful spirit from God is tormenting you.16 Let our lord now command your servants who are before you to seek out a man who is skillful in playing the lyre, and when the harmful spirit from God is upon you, he will play it, and you will be well.”17 So Saul said to his servants, “Provide for me a man who can play well and bring him to me.”18 One of the young men answered, “Behold, I have seen a son of Jesse the Bethlehemite, who is skillful in playing, a man of valor, a man of war, prudent in speech, and a man of good presence, and the LORD is with him.”19 Therefore Saul sent messengers to Jesse and said, “Send me David your son, who is with the sheep.”20 And Jesse took a donkey laden with bread and a skin of wine and a young goat and sent them by David his son to Saul.21 And David came to Saul and entered his service. And Saul loved him greatly, and he became his armor-bearer.22 And Saul sent to Jesse, saying, “Let David remain in my service, for he has found favor in my sight.”23 And whenever the harmful spirit from God was upon Saul, David took the lyre and played it with his hand. So Saul was refreshed and was well, and the harmful spirit departed from him.
