'Poisoned' in the Bible

Why are we just sitting here?Gather together; let us enter the fortified citiesand perish there,for the Lord our God has destroyed us.He has given us poisoned water to drink,because we have sinned against the Lord.

Therefore, this is what the Lord of Hosts says concerning the prophets:I am about to feed them wormwoodand give them poisoned water to drink,for from the prophets of Jerusalemungodliness has spread throughout the land.