Avner returns to Ish Boshet following the debacle at the pool in chapter 2, only to be greeted with a shocking accusation. Ish Boshet charges his general with sleeping with Shaul’s concubine, unfortunately named Ritzpah. Avner reacts with outrage, but it is not immediately clear whether his anger stems from the accusation being false or from Ish Boshet’s audacity in confronting him.
Metzudat Tzion believes that Avner did in fact sleep with Ritzpah. Since only the king could take possession of a royal concubine, Avner’s actions reflected an inflated sense of his own importance. Having installed Ish Boshet on the throne, Avner may have begun to view himself as the true power behind the kingdom. Under this reading, Avner is offended not because the accusation is false, but because he feels Ish Boshet is ungrateful for everything he has done on his behalf. In effect, Avner's response becomes: after all I have done for you, this is what you choose to challenge me about?
The alternative is that Avner never touched Ritzpah at all. In that case, his reaction reflects genuine shock. The house of Shaul came from the tribe of Binyamin, a tribe still haunted by the memory of the concubine of Givah and the near destruction that followed. Avner may have been appalled that Ish Boshet would accuse him of a transgression so closely associated with one of the darkest moments in Benjaminite history.
If Avner was innocent, why would Ish Boshet make such a charge? Perhaps the answer lies in the aftermath of chapter 2. Following the inconclusive battle between the forces of David and Ish Boshet, Ish Boshet may have sensed weakness in his powerful general. Seeing an opportunity to assert his own authority, he attempted to sideline Avner by floating a damaging accusation. It was a serious miscalculation. Instead of weakening Avner, Ish Boshet drove him into David’s camp.
Ish Boshet’s response in verse 11 underscores just how much power Avner wielded. "He could not answer Avner another word, because he feared him." In the first interpretation, Ish Boshet fears the reaction of a general he has just publicly accused of misconduct. He understands that Avner may now turn against him. In the second interpretation, the verse reveals a deeper truth: Ish Boshet had always been afraid of Avner. That fear led him to strike when he thought Avner was vulnerable, but when the plan failed, he still lacked the courage to confront him. Faced with Avner’s open defection, Ish Boshet could do nothing but remain silent.