3 So they searched throughout the land of Israel for a beautiful girl, and they found Abishag from Shunem and brought her to the king. 4 The girl was very beautiful, and she looked after the king and took care of him. But the king had no sexual relations with her.
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.