3 And they sought for a fair damsel throughout the territory of Israel, and found Abishag a Shunammite, and brought her to the king. 4 And the damsel was very fair; and cherished the king, and ministered to him; but the king knew her not.

Matthew Henry's Commentary on 1 Kings 1:3-4

Commentary on 1 Kings 1:1-4

(Read 1 Kings 1:1-4)

We have David sinking under infirmities. He was chastised for his recent sins, and felt the effects of his former toils and hardships.