There is not a single place in scripture which states that "the heart of the earth" is "hades".
Is the statement made by Jesus in Matthew 12:40 a prophecy?
Yes, the words of Matthew 12:40 KJB are a prophecy, but it is a special type of prophecy ~ a typological [dealing with type/antitype] one.
Notice carefully the prophecy that is clearly given, and the future tense thereof:
Now notice the typological aspect of the prophecy [the historic past portion which was to be repeated in anti-type, or greater reality/fulfillment]:
This means we can consider the texts of Matthew and Jonah in this light [typological prophecy] and look for those things which will help us identify terms, since prophecies are given in symbol, and things go from natural to spiritual as per 1 Corinthians 15:44-46 KJB.
Let us begin with the word “whale”. A “whale” according to the bible [KJB] is a great sea creature, a sea beast [Genesis 1:20-23; Job 7:12; Ezekiel 32:2; Matthew 12:40 KJB].
A beast/creature in prophetic terms/symbolism is generally a politically gathered/united people group/nation/kingdom [Genesis 49:9; Isaiah 27:1, 46:11; Jeremiah 4:7, 5:6, 12:8, 25:38, 49:19, 50:44; Ezekiel 17:3,7, 32:2; Daniel 7:7,19,23, 8:20,21; Joel 1:6; Micah 5:8; Revelation 13:1,2,3,7,11,12, 17:3,7,8,11,12, etc., KJB]. For a specific example, the Egyptians, as a nation, were designated under the symbol of a great sea creature:
[While reading, notice, God the Greatest Fisherman [doesn't Jesus know how to fish?, just ask Peter, James and John]]
[Pharaoh, as king [a head/husband] of a nation [a body/wife], represents the nation. Not only was this a prophecy of the past, but so also of the Future (events transpiring now; Daniel 11:40-45, 12:1, etc., KJB), and of the end of Satan himself.]
Also:
Now that we have seen that a “nation” [with its king] can be described as a “whale”, a sea creature/beast, let us see how that helps us in Matthew 12:40 and in Jonah, and how it helps us in relating the other terms, “in the heart of the earth”, “in the midst [heart] of the seas”, “whale's belly”, “the floods”, “thy billows” and “thy waves”.
First, let us consider this “earth” and what that means The “earth” [γηςG1093 N-GSF; earth, land, inhabited places, etc] - https://www.blueletterbible.org/lang...gs=G1093&t=KJV
Is the statement made by Jesus in Matthew 12:40 a prophecy?
Matthew 12:40 KJB - For as Jonas was three days and three nights in the whale's belly; so shall the Son of man be three days and three nights in the heart of the earth.
Yes, the words of Matthew 12:40 KJB are a prophecy, but it is a special type of prophecy ~ a typological [dealing with type/antitype] one.
Notice carefully the prophecy that is clearly given, and the future tense thereof:
“... so shall the Son of man be ...”
Now notice the typological aspect of the prophecy [the historic past portion which was to be repeated in anti-type, or greater reality/fulfillment]:
“For as Jonas was three days and three nights in the whale's belly ...”
This means we can consider the texts of Matthew and Jonah in this light [typological prophecy] and look for those things which will help us identify terms, since prophecies are given in symbol, and things go from natural to spiritual as per 1 Corinthians 15:44-46 KJB.
Let us begin with the word “whale”. A “whale” according to the bible [KJB] is a great sea creature, a sea beast [Genesis 1:20-23; Job 7:12; Ezekiel 32:2; Matthew 12:40 KJB].
A beast/creature in prophetic terms/symbolism is generally a politically gathered/united people group/nation/kingdom [Genesis 49:9; Isaiah 27:1, 46:11; Jeremiah 4:7, 5:6, 12:8, 25:38, 49:19, 50:44; Ezekiel 17:3,7, 32:2; Daniel 7:7,19,23, 8:20,21; Joel 1:6; Micah 5:8; Revelation 13:1,2,3,7,11,12, 17:3,7,8,11,12, etc., KJB]. For a specific example, the Egyptians, as a nation, were designated under the symbol of a great sea creature:
[While reading, notice, God the Greatest Fisherman [doesn't Jesus know how to fish?, just ask Peter, James and John]]
Ezekiel 32:2 KJB - Son of man, take up a lamentation for Pharaoh king of Egypt, and say unto him, Thou art like a young lion of the nations, and thou [art] as a whale in the seas: and thou camest forth with thy rivers, and troubledst the waters with thy feet, and fouledst their rivers.
[Pharaoh, as king [a head/husband] of a nation [a body/wife], represents the nation. Not only was this a prophecy of the past, but so also of the Future (events transpiring now; Daniel 11:40-45, 12:1, etc., KJB), and of the end of Satan himself.]
Ezekiel 32:3 KJB - Thus saith the Lord GOD; I will therefore spread out my net over thee with a company of many people; and they shall bring thee up in my net.
Ezekiel 32:4 KJB - Then will I leave thee upon the land, I will cast thee forth upon the open field, and will cause all the fowls of the heaven to remain upon thee, and I will fill the beasts of the whole earth with thee.
Ezekiel 32:5 KJB - And I will lay thy flesh upon the mountains, and fill the valleys with thy height.
Ezekiel 32:6 KJB - I will also water with thy blood the land wherein thou swimmest, [even] to the mountains; and the rivers shall be full of thee.
Ezekiel 32:7 KJB - And when I shall put thee out, I will cover the heaven, and make the stars thereof dark; I will cover the sun with a cloud, and the moon shall not give her light.
Ezekiel 32:8 KJB - All the bright lights of heaven will I make dark over thee, and set darkness upon thy land, saith the Lord GOD.
Ezekiel 32:9 KJB - I will also vex the hearts of many people, when I shall bring thy destruction among the nations, into the countries which thou hast not known.
Ezekiel 32:10 KJB - Yea, I will make many people amazed at thee, and their kings shall be horribly afraid for thee, when I shall brandish my sword before them; and they shall tremble at [every] moment, every man for his own life, in the day of thy fall.
Ezekiel 32:11 KJB - For thus saith the Lord GOD; The sword of the king of Babylon shall come upon thee.
Ezekiel 32:12 KJB - By the swords of the mighty will I cause thy multitude to fall, the terrible of the nations, all of them: and they shall spoil the pomp of Egypt, and all the multitude thereof shall be destroyed.
Ezekiel 32:13 KJB - I will destroy also all the beasts thereof from beside the great waters; neither shall the foot of man trouble them any more, nor the hoofs of beasts trouble them.
Ezekiel 32:14 KJB - Then will I make their waters deep, and cause their rivers to run like oil, saith the Lord GOD.
Ezekiel 32:15 KJB - When I shall make the land of Egypt desolate, and the country shall be destitute of that whereof it was full, when I shall smite all them that dwell therein, then shall they know that I [am] the LORD.
Ezekiel 32:16 KJB - This [is] the lamentation wherewith they shall lament her: the daughters of the nations shall lament her: they shall lament for her, [even] for Egypt, and for all her multitude, saith the Lord GOD.
Ezekiel 32:17 KJB - It came to pass also in the twelfth year, in the fifteenth [day] of the month, [that] the word of the LORD came unto me, saying,
Ezekiel 32:18 KJB - Son of man, wail for the multitude of Egypt, and cast them down, [even] her, and the daughters of the famous nations, unto the nether parts of the earth, with them that go down into the pit.
Also:
Isaiah 27:1 KJB - In that day the LORD with his sore and great and strong sword shall punish leviathan the piercing serpent, even leviathan that crooked serpent; and he shall slay the dragon that [is] in the sea.
Isaiah 27:12 KJB - And it shall come to pass in that day, [that] the LORD shall beat off from the channel of the river unto the stream of Egypt, and ye shall be gathered one by one, O ye children of Israel.
Now that we have seen that a “nation” [with its king] can be described as a “whale”, a sea creature/beast, let us see how that helps us in Matthew 12:40 and in Jonah, and how it helps us in relating the other terms, “in the heart of the earth”, “in the midst [heart] of the seas”, “whale's belly”, “the floods”, “thy billows” and “thy waves”.
First, let us consider this “earth” and what that means The “earth” [γηςG1093 N-GSF; earth, land, inhabited places, etc] - https://www.blueletterbible.org/lang...gs=G1093&t=KJV
Isa 63:1-4
63:1 Who is this that cometh from Edom, with dyed garments from Bozrah? this that is glorious in his apparel, travelling in the greatness of his strength? I that speak in righteousness, mighty to save.
2 Wherefore art thou red in thine apparel, and thy garments like him that treadeth in the winefat?
3 I have trodden the winepress alone; and of the people there was none with me: for I will tread them in mine anger, and trample them in my fury; and their blood shall be sprinkled upon my garments, and I will stain all my raiment.
4 For the day of vengeance is in mine heart, and the year of my redeemed is come.
KJV
On a different subject, I was trying to figure out who the Hittite and the Elamite symbolically referred to, in this passage. I thought about it last night. I wondered if possibly, the Hittite, might refer to Bathsheba, and the Elamite (ancestors of the Hebrews) to David.
Ezek 16:45
45 Thou art thy mother's daughter, that lotheth her husband and her children; and thou art the sister of thy sisters, which lothed their husbands and their children: your mother was an Hittite, and your father an Amorite.
KJV