Jeremiah 23:15
Therefore thus saith the LORD of hosts concerning the prophets; Behold, I will feed them with wormwood, and make them drink the water of gall: for from the prophets of Jerusalem is profaneness gone forth into all the land. Therefore thus saith the LORD of hosts concerning the prophets; Behold, I will feed them with wormwood, and make them drink the water of gall: for from the prophets of Jerusalem is profaneness gone forth into all the land.
Jeremiah 23:15 stands within Jeremiah 12–24, the portion that gives warnings to the Jews. In its setting it concerns false prophets who proclaim peace and assurance when danger is present. Those prophets speak visions from their own hearts rather than from the Lord.
From the prophets of Jerusalem profaneness has gone forth into all the land. They are a source of profaneness spreading throughout the land, profaning sacred things and leading people astray, with the corruption beginning with Jerusalem's prophets. To feed them with wormwood and make them drink the water of gall means God will punish prophets who corrupt His message, wormwood and the bitter water of gall signifying the bitter judgment awaiting them. The people are therefore warned not to heed them.