Was being cured so noteworthy to warrant Seforim and a gift?
Rashi (Melachim II, 20:12): Until that time, no one became ill and recovered. 1
Radak (Melachim II, 20:12), Malbim: He sent primarily due to the wonder (the sun going back), like it says "Lidrosh ha'Mofes 2 " (Divrei ha'Yamim II, 32:31).
So say Pirkei d'R. Eliezer 52 and Bereishis Rabah 65:9. Refer to 39:1:2:1-3, 39:1:3:1-7, 39:1:4:1-3.
Malbim: Melech Bavel did not send amidst love. Chizkiyah said that they came from afar (verse 3), i.e. he had no prior connection with them. Bavel was close with Ashur; they still bore ill will due to Sancheriv's demise. He sent to understand the power of the nation.
Rashi (Melachim II, 20:12) writes that until Chizkiyah, no one became ill and recovered. Bava Basra 16b says that Avraham had a special stone. Any sick person who looked at it was be cured immediately! Shlomo had written Sefer ha'Refu'os! Asa sought doctors when he was sick (Divrei ha'Yamim II, 16:2)! Yaravam asked if his son will recover, and Melech Aram asked about himself (Melachim II, 8:8)!
Tosfos (16b) #1: Earlier 1 , people recovered only from illness due to a blow.
Tosfos (16b) #2: Earlier, people recovered from illness, but not from mortal illness 2 .
Refer to 39:1:3:1,3,6.
Tosfos resolved Bava Basra with Bava Metzi'a 87a, which says that Elisha was the first to recover. His answers can resolve Bava Basra also with the Midrash that says that Chizkiyah was first. (PF)
Nezer ha'Kodesh (on Bereishis Rabah 65:9): This is why Yeshayah needed to tell Chizkiyah that he will die. I.e. know that your illness is a mortal illness!
Rashi (Melachim II, 20:12) writes that until Chizkiyah, no one became ill and recovered. Bava Metzi'a 87a and Sanhedrin 107b say that Elisha was the first!
Yefe To'ar (on Bereishis Rabah 65:9) and Pesach Einayim (107b): Before, people recovered only from injuries, but not when the entire body was ill.
Be'er-Sheva (107b): Some call Chizkiyah the first, for it is not explicit in the verses that Elisha recovered.
Anaf Yosef (107b, citing Kli Yakar):, Before, people could continue to live amidst the illness, but they did not return to health.
Anaf Yosef (87a): Elisha himself was cured, but Chizkiyah asked that this become 'the way of the world' that people can recover, and Hashem fulfilled this.
Ha'Rif (87a) #1: After Elisha, people were cured via Sefer ha'Refu'os. Chizkiyah hid it, and asked that people be cured via Tefilah.
Ha'Rif (87a) #2: Chizkiyah was the first to recover after a decree that he will die from his illness.
Refer to 39:1:2:2.
Rashi (Melachim II, 20:12) writes that until Chizkiyah, no one became ill and recovered. The Torah commands "v'Rapo Yerapei" (Shemos 21:19)! Brachos 54b learns from "Yishlach Devaro va'Yirpa'em" (Tehilim 107:20) that a Choleh who recovered must bring a Todah!
Yefe To'ar (on Bereishis Rabah 65:9) #1: The verses apply after Chizkiyah.
Yefe To'ar (on Bereishis Rabah 65:9) #2: Before Chizkiyah, the verses applied to recovering from injuries 1 .
Nezer ha'Kodesh (on Bereishis Rabah 65:9): Tosfos (Bava Basra 16b) said that earlier, people recovered from illness, but not from mortal illness.
Refer to 39:1:3:6.
Nezer ha'Kodesh (on 65:9): The verse in Tehilim implies that it discusses an illness from Shamayim!
Here it says "Merodach". In Melachim II (20:12) it says "Berodach"!
Radak (Melachim II, 20:12): They are the same. Beis and Mem are interchangeable. They are pronounced from the same place (the lips - PF).
Who was Bal'adan?
Radak: He was Merodach's father; this is a nickname added to Merodach. He 1 was Esar Chadon, Sancheriv's son who ruled after him (37:38). He was king over Bavel, for in the days of Menasheh, it says "came upon them Sarei ha'Tzava of Melech Ashur
It seems that 'he' refers to Merodach; if so Sancheriv was also called Bal'adan. Sanhedrin 94a lists many names of Sancheriv. Bal'adan is not among them! The Midrash (refer to 39:1:7:1) implies that Merodach was king at the time of the wonder. This was before the fall of Sancheriv's army! Was Sancheriv's son king of Bavel in his father's lifetime? It seems that Radak explains unlike the Midrash. After Merodach became king, after his father died, he heard that the wonder was done for Chizkiyah, and he sent Seforim. (PF)
How did he hear about the cure of Chizkiyah?
Rashi citing Tanchuma and Ki Sisa 5: He used to eat at three hours of the day, and sleep until nine hours. He woke, and found that it is morning. He wanted to kill his servants for letting him sleep the entire day. They told him that the sun went backwards, due to 1 Chizkiyah 2 .
Surely, at first they told him only that the sun went backwards, and they learned the reason only later. Sancheriv came [to Yehudah] two weeks before Pesach, so they could not seed (Seder Olam 23). All the more so they would not endanger a Shali'ach to go from Yerushalayim to Bavel to inform Nochrim about the miracle! Also, how could a Shali'ach (even on a fast camel) reach there in a few hours (it was still the new morning)? It takes two weeks for Olei Regalim to return from Yerushalayim to the Pras river (Ta'anis 1:3)! Also, surely it was known that Sancheriv planned to conquer Yerushalayim and punish Chizkiyah. Would one send a gift at such a time?! Also, Nebuchadnetzar ran to stop the Shali'ach and rewrite the letter, but he was stopped. Nebuchadnetzar was one of the survivors when Sancheriv's camp was wiped out (Sanhedrin 95b-96a), two days after the wonder! (PF)
Malbim: Divrei ha'Yamim II, 32:25 says that Chizkiyah because haughty when they sent to him. He attributed the wonder to himself, a sign that he will be cured. Really, it was a sign for the nation, that Hashem will save them from Sancheriv! Due to this, Melech Bavel thought that Hashem does not desire Yisrael, rather, Chizkiyah. Therefore, he did not return the Jews exiled in his land, and once Chizkiyah died, he did not fear to confront Menasheh. Hashem would have made him Mashi'ach had he sung Shirah (Sanhedrin 94a) - i.e. had he sung over the fall of Sancheriv, and not for his salvation from his illness (38:9-20)!
