2 Samuel 13:5
And Jonadab said unto him, Lay thee down on thy bed, and make thyself sick: and when thy father cometh to see thee, say unto him, I pray thee, let my sister Tamar come, and give me meat, and dress the meat in my sight, that I may see it, and eat it at her hand.
Jonadab devised a deceitful plan for Amnon to lie down on his bed and make himself appear sick, and when his father came to see him to ask that his sister Tamar be allowed to come and dress food in his sight so he might see it and eat it from her hand. That counsel sets the stage for and belongs to the account of Amnon's crime against Tamar and the revenge that followed it.
David allowed Amnon's crime to go unpunished. The great crime and its consequences brought David bitter grief. In revenge Absalom concealed his purpose for two years before ordering Amnon's death at a feast.