John Gill's Exposition of the Whole Bible
Isaiah 39:1
At that time Merodachbaladan, the son of Baladan, king of Babylon,.... The same is called Berodach, 2 Kings 20:12 which, according to Hillerus z, is the same with Barmerodach, the son of Merodach; though it is generally took to be a slip of the scribe's there, or a change of letter, as is common in names; he was either afterwards made a god of, or he had his name from an idol of the Babylonians so called, Jeremiah 50:1, which signifies "a pure lord." Jerom observes it, as the opinion of the Jews, that he was the father of Nebuchadnezzar, which is not probable. Kimchi takes him to be the same with Esarhaddon, the son of Sennacherib; but he was king of Assyria, not of Babylon; it is most likely that he is the Assyrian king, whom Ptolemy in his canon calls Mardocempad; his other name Baladan, which is compounded of two words, "bal" and "adan", and both of them signify lord, he took from his father, for he is called the son of Baladan; by Josephus a he is called Baladas, who says that Berosus the Chaldean makes mention of a king of Babylon by this name. Bishop Usher b thinks he is the same that is called by profane writers Belesis, and Belessus, and Nabonasarus; his name consists of the names of three idols, Merodach, an idol of the Babylonians, as before observed, and Bal, the contraction of Baal, and Adon, the same with Adonis:
he sent letters and a present to Hezekiah; by his ambassadors, which was always usual in embassies and visits, and still is in the eastern countries; the purport of which embassy was to congratulate him upon his recovery, and to inquire concerning the miracle that was wrought in his land; either the destruction of the Assyrian army in one night by an angel, or rather the sun's going back ten degrees, 2 Chronicles 32:31 and, as Josephus c says, to enter into an alliance with him; and this seems to be the true reason of sending these ambassadors; or the king of Babylon had lately fallen off from the Assyrian monarch, and therefore was desirous of entering into a league with Hezekiah the king of Assyria's enemy, in order to strengthen himself against him, and secure his liberty he had just gained:
for he had heard that he had been sick, and was recovered; which both gives a reason of the embassy, and points at the time when it was; very probably the same year of his sickness and recovery.
z Onomast. Sacr. p, 603. a Antiqu. l. 10. c. 2. sect. 2. b Annales Vet. Test. p. 87, 88. c Ibid.