Zedekiah's Hard Heart

2 Chronicles 36:13
He also rebelled against King Nebuchadnezzar, who had made him take an oath in God's name. He became stiff-necked and hardened his heart and would not turn to the LORD, the God of Israel.

He is Zedekiah, uncle of Jehoiachin, a grandson of Josiah. The prophesied ruin has come fast. Since Josiah, the kings have been evil and detestable. Adding to his other sins, Zedekiah hardened his heart. This has happened before; when Pharoah hardened his heart, I reasoned from the surrounding events that it involves a refusal to acknowledge God. Here it is spelled out. He could have listened to Jeremiah, and he could have bowed to God's will in placing Nebuchadnezzar over him. But he refused to see God at work.
The rot proceeded from the head of the fish on down. The Temple was looted and burned, and so were the palaces.
And the next book is named "Ezra."

Covenant Heart

2 Chronicles 34:31
The king stood by his pillar and renewed the covenant in the presence of the LORD -to follow the LORD and keep his commands, regulations and decrees with all his heart and all his soul, and to obey the words of the covenant written in this book.
Verse 30 speaks of the Book of the Covenant that Josiah read to everyone crowded into the Temple--all Israelites, from the least to the greatest. I looked up that phrase itself: "Book of the Covenant." It appears only 4 times total. The first is in Exodus 24:7, when Moses reads it to the Israelites. Matthew Henry suggests that Moses had himself just written it, so as to be sure it is exactly as God said it.
The other 3 times are this occasion, when Josiah reads it, and it is as if it was just written. I am struck here that it is the king who renews the covenant. If any one person should, I suppose it would be the king. The next verse says he had all the people do it as well, and they did.
As long as Josiah lived, the people served

Responsive Heart

2 Chronicles 34:27
Because your heart was responsive and you humbled yourself before God when you heard what he spoke against this place and its people, and because you humbled yourself before me and tore your robes and wept in my presence, I have heard you, declares the LORD.

This is good King Josiah. Between him and good King Hezekiah was the bad King Manasseh in chapter 33. The interesting thing I find about him is that he did start out very bad, undoing all of Hezekiah's reforms and re-establishing idol worship, but then he made a turnaround. After being taken away to Babylon, shackled, hook in nose, he humbled himself and pleaded with God. My thought is, who wouldn't? God's mercy is dazzling. With no details given, Manasseh returned to Jerusalem and showed himself a changed man, reversing much of the pagan worship he'd brought in himself.
His son, another bad king, was so bad that he got only two years.
And that is the background for this, Josiah's responsive heart. Again, I find the sequence of events very intriguing. Josiah was the boy king, only eight when he started. At sixteen, he began to seek the Lord. At twenty he went out and purified the land physically as Hezekiah had. Six years later he began to repair the Temple. This work went well, but it was only as they brought out money from the Temple that the Book of the Law turned up. In the same afterthought way, Shaphan brought Josiah an update on the Temple work and the finances, and then, oh yes, they found this book.
How did Josiah know where to start without the Book, without even knowing it existed? God Himself must have led him...
I picture these elite men of Judah, staring for a few minutes at a dusty scroll, knowing before they opened it that it was worth more than all the silver and gold, more than the whole Temple, that it was the very Word of God. And when the good king heard the words, he tore his robes.
Josiah's reward was for him and his generation--(v.28) "Now I will gather you to your fathers, and you will be buried in peace. Your eyes will not see all the disaster I am going to bring on this place and on those who live here." There wasn't enough mercy for the future idolaters, who would indeed live through disaster.