3 So they searched the country of Israel for the most ravishing girl they could find; they found Abishag the Shunammite and brought her to the king. 4 The girl was stunningly beautiful; she stayed at his side and looked after the king, but the king did not have sex 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.