Asa would have had his workers gather the gold and silver for him. Alternate translation: "Then Asa told his workers to take the silver ... of the king's house, and to take it" (See: [[rc://en/ta/man/jit/figs-metonymy]])
This means he spoke by means of his servants. Asa told his servants what to say to Ben-Hadad and they did. The meaning of this can be made clear. Alternate translation: "Asa told his servants to say to Ben-Hadad" or "Through his servants, Asa said to Ben-Hadad" (See: [[rc://en/ta/man/jit/figs-metonymy]] and [[rc://en/ta/man/jit/figs-explicit]])