Albert Barnes Commentary 2 Kings 9:18

"So there went one on horseback to meet him, and said, Thus saith the king, Is it peace? And Jehu said, What hast thou to do with peace? turn thee behind me. And the watchman told, saying, The messenger came to them, but he cometh not back." — 2 Kings 9:18 (ASV)

What have you to do with peace? — that is, “What does it matter to you whether my errand is one of peace or not?”