I have seen folly in the prophets of Samaria - This was not to be wondered at, for their religion was a system of corruption.
And I have seen folly - Rather, “Also I have seen.” The prophet contrasts the prophets of Samaria with those of Jerusalem. In the conduct of the former God saw folly (literally that which is insipid, as being unsalted). It was stupidity to prophesy by Baal, an idol.
In Baal - i. e., in the name of Baal.