Albert Barnes Commentary Isaiah 39:3

"Then came Isaiah the prophet unto king Hezekiah, and said unto him, What said these men? and from whence came they unto thee? And Hezekiah said, They are come from a far country unto me, even from Babylon." — Isaiah 39:3 (ASV)

Then Isaiah came — Isaiah was accustomed to declare the will of God most freely to monarchs .

What did these men say? — What proposition have they made? What is the purpose of their coming? It is implied in the question that there had been some improper communication from them. To this question Hezekiah returned no answer.

And from where did they come? — It was undoubtedly known in Jerusalem that ambassadors had come, but it would not likely be known from what country they had come.

From a far country — Probably this was said to palliate and excuse his conduct, by intimating to the prophet that it was proper to show respectful attention to foreigners, and that he had done nothing more than was demanded by the laws of hospitality and kindness.