16 “Anyone who kidnaps someone is to be put to death, whether the victim has been sold or is still in the kidnapper’s possession.

Read Exodus 21:16 Using Other Translations

And he that stealeth a man, and selleth him, or if he be found in his hand, he shall surely be put to death.
"Whoever steals a man and sells him, and anyone found in possession of him, shall be put to death.
“Kidnappers must be put to death, whether they are caught in possession of their victims or have already sold them as slaves.