Did King Hezekiah do something wrong in showing off his wealth?

The Hezekiah (Heb: Chizkiyahu) narrative in II Kings (chapters 17 – 20) and Isaiah (36 – 39) concludes on a dissonant and haunting confrontation between King Hezekiah and the prophet Isaiah. Hezekiah has just shown his kingdom’s wealth to messengers of Brodach Baladan, King of Babylonia. Isaiah asks Hezekiah about his guests, and when Hezekiah tells him where they are from, Isaiah proclaims:

Behold, days are coming and everything in your house and what your
ancestors have collected until this day will be carried off to
Babylonia, nothing will remain saith the Lord. And the children that
you will beget will be taken to be eunuchs in the palace of the King
of Babylonia. And Hezekiah responded to Isaiah, the word of the Lord
that you have spoken is good, insomuch as there will be peace and
truth in my days. (II Kings 20:17-18, JPS translation).

This prophecy of doom is devastating and perplexing. Does Isaiah mean to say that Hezekiah is literally responsible for the future exile and destruction at the hands of Babylonians? If so, what did he do wrong? How should Hezekiah have known it was bad to receive foreign emissaries from Babylonia?

Is DEATH Singular or Plural in Isaiah 53:9 and What is it’s Meaning?

Isaiah 53:9 says, “וַיִּתֵּ֤ן אֶת־רְשָׁעִים֙ קִבְרֹ֔ו וְאֶת־עָשִׁ֖יר בְּמֹתָ֑יו עַ֚ל לֹא־חָמָ֣ס עָשָׂ֔ה וְלֹ֥א מִרְמָ֖ה בְּפִֽיו׃(Westminster Leningrad Codex)

“Violence not Because in his death the rich and with his engrave the wicked with And he made in his mouth (was any) deceit neither he had done.”(Interlinear)

I am not a Hebrew Scholar, but my understanding, as well as the common translations say that בְּמֹתָ֑יו is singular, yet the BDB lists the יו as being plural.
If my assumption is correct, then why was בְּמֹתָ֑יו(death) translated Singular, and what would this passage mean if it were understood in the plural?

What scripture is Paul referring to in Ephesians 5:14?

In Ephesians we find that light (religious truth) is described as very powerful as it is able to make dead things living just by shining on them.

But when anything is exposed by the light, it becomes visible, for anything that becomes visible is light. Therefore it says,
“Awake, O sleeper,
and arise from the dead,
and Christ will shine on you.”

(Ephesians 5:13-14, ESV)

However, this is no direct quote of any biblical passage, so I imagine Paul simply puts it in his own words to apply it to the context. But what is ‘it’; what scripture is he paraphrasing here which fully suits the context? Why is it an appropriate verse to quote in this context?

What is the stump of Jesse?

A shoot will come up from the stump of Jesse;
from his roots a Branch will bear fruit.

Isiah 11:1 (NIV)

Question 1:
What does this “stump” refer to?

Question 2:
I think it is referring to that the trunk of the Me…