11 And king David 'is' old, entering into days, and they cover him with garments, and he hath no heat, 2 and his servants say to him, 'Let them seek for my lord the king a young woman, a virgin, and she hath stood before the king, and is to him a companion, and hath lain in thy bosom, and my lord the king hath heat.' 3 And they seek a fair young woman in all the border of Israel, and find Abishag the Shunammite, and bring her in to the king, 4 and the young woman 'is' very very fair, and she is to the king a companion, and serveth him, and the king hath not known her.
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.