This seems to mean that Jeremiah was to send a set of fetters and yoke to each king listed. But some versions of the Bible translate this as "Then send out messages."
# Send them by the hand of those kings' ambassadors who ... Judah
The hand is a synecdoche for the person. Alternate translation: "Have those kings' ambassadors, who ... Judah, take them" (See: [[rc://en/ta/man/jit/figs-synecdoche]])