Albert Barnes Commentary 1 Kings 21:9

"And she wrote in the letters, saying, Proclaim a fast, and set Naboth on high among the people:" — 1 Kings 21:9 (ASV)

The purpose of this fast was both to create prejudice against Naboth, whom the elders assumed had disgraced the town, and at the same time to give the proceedings an air of religion, which might blind people to their actual injustice.

Set Naboth on high among his people - This was not an order to give Naboth any honor, not even an apparent one; it was simply a command to bring him forward before a court or assembly, where he might be seen by all, tried, and condemned.