Jeremiah 19

1 God wants to speak to the political and spiritual leaders of Judah.
2 This is the location of the dump on the southern side of Jerusalem. Specifically, this gate is where clay vessels were thrown out.
3 The term "king" here may refer to the actual past, present, and future kings of Judah, but it seems more likely that Jeremiah is using this term to address those who rule the people. In this case the term may be used either with reverence or sarcasm, but it is impossible to know from the written words.

Like any big disaster story, people will become engrossed with how Judah and Jerusalem were destroyed.

4 God tells Judah in no uncertain terms that He will destroy Judah because of their idolatry. It seems that the Jews of the time were willing to worship any new idol they were introduced to, but would not listen to or obey the one true God who had been so important to their ancestors.

The blood of the innocent could refer both to those who were wrongly accused and executed in the courts, and to the blood of children that were offered in sacrifice to idols.

5 The only human sacrifice ever sanctified by God was the sacrifice of His Son, Jesus. Murder done in the name of religion is utterly detestable to God.
6 The battle that was to take place here would be so violent that the valley would be renamed after it.
7 The people would be completely destroyed. Their bodies would not be buried either out of deliberate dishonor or because the enemies would kill them faster than they could be buried.
8 I don't know if hissing refers to disdain or to pity.
9 To add to the horrors of war, cannibalism would become rampant during the siege of Jerusalem.
11 Most people prefer an honorable burial, but the inhabitants of Jerusalem would be buried in open graves in the city landfill.
12 Jerusalem itself would become like a dump -- unclean before God and detestable before men.
13 One may wonder why God did not judge the other nations who did these evil things. God certainly will judge them, but the Jews were a special case. God had specifically appeared to Israel and had given them His commands directly. He had given them land and provided them with many evidences of His existence and power. Yet, the people did not persist in belief. God's judgement begins with those who had the clearest revelation, but those who had less understanding will not escape punishment. The Jews of this time suffered terrible punishment, but this is a warning to us and the survivors of that nation that there is a fate even worse than that for those who are found without faith on Judgement Day.
14 Jeremiah spoke with the leaders at the town dump, but he spoke with the common people in God's Temple.
15 Again Jeremiah sounds the warning for all the people. They were becoming like stubborn mules that were going where they wanted and could not be led where they were supposed to go.