Iron, Fire, Water and Salt, Descended from Heaven

Imam ad-Daylamy in "al-Firdaws', Imam as-Sihti in “Jam al-Jawâmi”, Ibn Kathîr in “al-Kâfî ash-Shâfî fî Takhrij Ahdidith al-Kash-shdifʼ, Imâm al-`Aglüni in “ʻKashfal-Khafôiʼ and Imam al-Qurtübi in his "Tafsir' reported that the Prophet is said,
"Allah has sent down from the heavens to the earth four blessed things: Iron, fire, water and salt.”

Explanation of the Hadith

Even though this hadith is weak concerning its Isnad (chain of narrators), it still has an early reference to a great scientific sign. People who heard this hadith at the time of the Prophet were able to perceive the idea of fire, water and salt being sent from heaven to earth. Nevertheless, they could not perceive the idea of iron being sent from heaven to earth, even though the Qur'an refers very clearly to this issue, as Allah, Glorified be He, says,

(And we sent down iron wherein is mighty power as well as many benefits formankind ... (Al-Hadid: 25)

That is why most of those who explained this Qur’anic verse and this hadith, interpreted the "sending down as being a metaphor to refer to the creation of iron.
However, in the last decades of the 20" century, astronomers and astrophysicists started to study the chemical structure of the perceived part of the universe. To all their surprise they found that the most predominant element is Hydrogen gas (the lightest and most simple element), forming 74% of the matter of the perceived universe. Then, comes Helium gas (the second element in the periodic table), which forms 24%, and the rest of the elements (estimated to be 105 elements) form less than 2% of the matter of the universe. This observation led to a logical deduction, that all known elements were created from Hydrogen gas, by its self. condensation, and by the fusion of its nuclei.

It has been proven that the Sun's fuel is hydrogen gas whose nuclei fused to form the nuclei of Helium, thus releasing an enormous amount of energy. This released energy causes the core of the sun to have a temperature estimated to be almost 15 million degrees centigrade, the Sun's surface to have a temperature of 6,000 degrees centigrade, while the fire flames bursting from the inside of the sun, have a temperature of almost million degrees centigrade. It has also been proven that nuclear fusion inside the core of the Sun never produces any heavy elements, let alone producing iron. The only element, which is produced inside the Sun through this fusion process, is Helium along with a small amount of the elements, which follow Helium in the Periodic Table.

The question, which arises here, is: where has all this enormous amount of iron come from? This amount exceeds 1/3 of the mass of the earth which is estimated at 6,000
million million million ton (i.e. 6X10X35.9 = 2, 154 X 10 ton of iron). Extensive studies proved that stars go through several stages in their life span. In some of these stages, stars become very luminous, and are known as “Novas” and "Supernovas', and that the temperature of the star's core at that stage exceeds tens of billions of degrees. The cores of these “Novas” and “Supernovas”, are the only place known to us in the perceived part of the universe, where these nuclear fusion reactions take place, until the core of the star transforms totally into iron. Through this transformational process, the total energy of the star is used up leading to its explosion, and the scattering of its parts throughout the universe.

Throughout this process, iron reaches many celestial bodies, such as the earth, exactly the same way as iron meteors reach the earth nowadays. This accurate observation eventually led to an accurate theory, which presumes that when the earth was separated from the sun (or from the celestial cloud which is the origin of our solar system), it was nothing but a pile of ash, that had no elements higher than Aluminum and Silicon, and then it was bombarded by a stream of iron meteors, rocky meteors and other meteors formed from rocks and iron. Due to the high density of these meteors, (which is higher than that of the earth in its preliminary ash status) they moved down to the center of the pile of ash, where they melted because of their homoeothermic state. This led to the fusion of the pile of ash dividing it into seven earths: A hard core (90% iron, 9% Nickel, 1% other elements), and a soft liquefied core (which has the same chemical structure). Next to that are three consecutive spheres (mantles), where the ratio of iron decreases as you go from the inside to the outside.
Following these spheres is the lower part of the lithosphere, followed by the upper part of the lithosphere (i.e. the earth's crust which contains 5.6% iron).

It is through these accurate observations that it has been proven that all of the iron on the earth has been literally sent down from heaven, assuring what was mentioned in the Qur'an and the hadith of the Prophets
If were it not for this iron, the earth would not have had this magnetic field, which holds its gaseous atmosphere and its liquid hydrosphere as well as all other forms of life on its surface. If were it not for the iron being sent down, there would be no life on earth as iron forms a very important constituent of the hemoglobin of man and many other animals. It also forms an important constituent of chlorophyll, which is vital for the life of plants.

This critical scientific sign found in the Glorious Qur'an and in this Prophetic hadith, that came fourteen hundred years ago, testifies to the true Prophethood of Muhammad is and the Divinity of his Message.