NET
29 Moreover the Lord says, ‘I will make something happen to prove that I will punish you in this place. I will do it so that you will know that my threats to bring disaster on you will prove true.
Darby
29 And this shall be the sign unto you, saith Jehovah, that I will punish you in this place, that ye may know that my words shall certainly stand against you for evil:
KJV
29 And this [shall be] a sign unto you, saith the LORD, that I will punish you in this place, that ye may know that my words shall surely stand against you for evil: