This verse seems to refer to the events in 2 Kgs 20.12-19 and Isa 39, which tell a story about Babylonian ambassadors visiting Hezekiah.
And so translates the common conjunction and an adverb in Hebrew. These words been interpreted in different ways in this context. And so suggests a continuation of the thought that Hezekiah prospered in all that he did. Good News Translation is similar with “and even.” Other translations include “Nevertheless” (New American Bible) and “although” (New Jerusalem Bible), which introduce a contrast with the preceding statement.
In the matter of the envoys of the princes of Babylon, who had been sent to him to inquire …: Babylonian envoys were sent to Hezekiah to make inquiries of him. The words the matter of are not in the Hebrew text, but are supplied by Revised Standard Version. Instead of the princes of Babylon, some scholars think the Hebrew originally read “the king of Babylon” in agreement with the parallel text in 2 Kgs 20.12 (so Revised English Bible). Good News Translation renders the envoys of the princes of Babylon as “the Babylonian ambassadors” to avoid the difficulty. With regard to this textual problem, Critique Textuelle de l’Ancien Testament gives a {B} rating to “the princes of Babylon.” In this context the Hebrew word for princes is better rendered “officials” ( NET Bible) or “leaders” (New Century Version); see the comments on 1 Chr 19.3 and 2 Chr 12.5. For Babylon see the comments on 1 Chr 9.1.
The passive verb had been sent may be made active as by making explicit the agent who had sent them; for example, New Century Version begins this verse with “But one time the leaders of Babylon sent messengers to Hezekiah….”
The sign that had been done in the land: This clause probably refers to the event told in 2 Kgs 20.8-11. See the comments on verse 24.
God left him to himself is a way of saying that God did not intervene in the matter. This clause may be expressed by as “God withdrew from Hezekiah” (New Living Translation) or “God did not act.”
In order to try him: God did not intervene “to test him” (God’s Word). Here the verb to try conveys the idea of a test, a kind of experimentation to prove the character of Hezekiah.
And to know all that was in his heart: This clause explains more fully the previous one. God allowed Hezekiah to go his own way “to see if he would remain faithful” (Contemporary English Version). It was an attempt to “find out all that was in his mind” (Moffatt).
Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on 1-2 Chronicles, Volume 1. (UBS Helps for Translators). Miami: UBS, 2014. For this and other handbooks for translators see here .