Perek 37: Chizkiyahu asks Yeshaya to pray for the survivial of Yerushalayim from the attack of Ashur. Ashur withdraw to fight a different war. Yeshaya prophecy about Ashur’s downfall and Chizkiyahu’s success. The angel striking down the camp of Ashur overnight.
Perek 38: Chizkiyahu’s illness and recovery, and song of thanks to HaShem.
Perek 39: Chizkiyahu shows the king of Bavel all his treasures and is rebuked.
Perek 40: Prophecy of times of Moshiach, and of exile, and praises of HaShem.
Perek 41: The trial of the nations by HaShem, and Israel’s special status as HaShem’s People.
Perek 42: The Moshiach. Light unto the nations. Song of redemption. Israel’s degradation in exile.
Perek 38 tells us about Chizkiyahu’s mysterious illness, and about how he eventually recovers from it and gives birth to a son. What was happening here? The gemarra (Brachos) fills in the details here. This illness was part of HaShem’s punishment for Chizkiyahu. What did he do wrong? He did not want to have any children; in violation of the Torah command to ‘be fruitful and multiply;’ a very important mitzvah. But why did he want to go against this commandment? Because he saw that his son would be evil (he was right – his son did turn out to be evil; the future idolatrous king Menashe), and so decided that it would be better for him not to have any children than to have an evil child like this who would go down in Jewish history for all the wrong reasons. But still, Chizkiyahu was punished for he was incorrect on this one. As Yeshayahu told him ‘you are not to look into HaShem’s Plans;’ whether your son will be evil or not is not to be taken into account. HaShem gave you a mitzvah and it must be done, regardless of any personal calculations. This is a message for us too; we are not supposed to start putting in our personal calculations in trying to avoid a mitzvah (e.g. ‘it’s too hard, HaShem surely would not expect me to do this…’). HaShem gave us a mitzvah and that’s the end of the story. He commands and we do; there’s no room for our personal calculations.