This verse contains David’s instruction to Solomon regarding Shimei. Some English translations read, Do not let him go unpunished,
but others, like the ESV, read, Do not hold him guiltless.
The Hebrew would allow either translation. If we follow the ESV, we may first see David’s true estimation of Shimei’s repentance. Solomon should not hold him guiltless because he is in fact guilty.
Yet David did not instruct Solomon to revoke the pardon. There probably was no outward evidence to prove Shimei’s insincerity. Instead, David called upon Solomon to exercise his wisdom in such a manner that Shimei would be forced to eventually show his true rebelliousness. His death would not be the result of the old offence, but the command of Solomon as well as his own free agency would bring about his death. It would be within his power to escape the punishment of the Davidic dynasty, so his death will be on his own head.
There is a final word needed concerning 1 Kings 2:5–9. Absent from the list of names that David commanded his son on which to take action is the name of Adonijah. His treason was much fresher than that of Shimei or of Joab that David did note (he did not note Joab’s part in Adonijah’s conspiracy, 1 Kings 1:7). Why was this omission the case? Solomon had already sworn to his brother that no harm would come to him if he showed himself a worthy man. At the time of David’s commands to Solomon, Adonijah apparently remained on good behaviour. Yet, the future would tell a different story (1 Kings 2:24–25).
9 Now therefore do not hold him guiltless, for you are a wise man. You will know what you ought to do to him, and you shall bring his gray head down with blood to Sheol.”