11 King David was old and advanced in years; and although they covered him with clothes, he could not get warm. 2 So his servants said to him, "Let a young virgin be sought for my lord the king, and let her wait on the king, and be his attendant; let her lie in your bosom, so that my lord the king may be warm." 3 So they searched for a beautiful girl throughout all the territory of Israel, and found Abishag the Shunammite, and brought her to the king. 4 The girl was very beautiful. She became the king's attendant and served him, but the king did not know her sexually.
Matthew Henry's Commentary on 1 Kings 1:1-4
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.