Adam Clarke on 2 Samuel 16:4

Thine are all - This conduct of David was very rash; he spoiled an honorable man to reward a villain, not giving himself time to look into the circumstances of the case. But David was in heavy afflictions, and these sometimes make even a wise man mad. Nothing should be done rashly; he who is in the habit of obeying the first impulse of his passions or feelings, will seldom do a right action, and never keep a clear conscience.