Charles Ellicott Commentary 2 Samuel 12:10

"Now therefore the sword shall never depart from thy house, because thou hast despised me, and hast taken the wife of Uriah the Hittite to be thy wife." — 2 Samuel 12:10 (ASV)

Shall never depart. —This word, in both its positive and negative forms, for ever and never, is constantly used to express the longest time possible in connection with the subject it is used with. Here it must mean “as long as David lives”; and the punishment denounced found its realization in a long succession of woes, from the murder of Amnon to the execution of Adonijah.