What is the meaning of

What is the meaning of 2 Samuel 3: 33: “Died Abner as a fool dieth?”

Probably the thought is: “Did Abner die like an inexperienced fool, who knew not how to defend himself?” And the intended answer is, “No, he fell victim to a deceitful wicked plot.” Compare verse 27, in which the unsuspicious nature of Abner stands in marked contrast to the suspicions Joab had expressed concerning him in verse 25. Notice, too, that he was slain in the last place where it might have been expected he would be, in the gate of Hebron which was a city of refuge (Joshua 20:7), as well as being the residence of king David at that time.
Yet there is no doubt that Abner did really act as a fool on an earlier occasion, when he made the unwise choice of chap. a. 8, 9 for Ishbosheth and against David, and did so deliberately though he well knew (see chap. 3. 9, xo) what the mind of God in the matter was.