In the first sample for Isaiah chapter 39, the Lord makes a connection to the 39th Christian book with a warning from the LORD of hosts that behold the days come that nothing shall be left.
ISAIAH 39:5
…Hear the word of the LORD of hosts:
6 Behold, the days come, that all that is in thine house… shall be carried to Babylon: nothing shall be left, saith the LORD.MALACHI 4:1
For behold the day cometh that shall burn as an oven… and the day that cometh shall burn them up, saith the LORD of hosts, that it shall leave them neither root or branch.
In the second sample for Isaiah chapter 39, the Lord makes a connection to the 39th Jewish book with Hezekiah being sick unto death and the Lord healing him.
ISAIAH 39:1
At that time…king of Babylon, sent letters and a present to Hezekiah: for he had heard that he had been sick, and was recovered.II CHRONICLES 32:24
In those days Hezekiah was sick to the death, and prayed unto the LORD: and he spake unto him, and he gave him a sign (a miracle).
25 But Hezekiah rendered not again according to the benefit (act of kindness) done unto him…