On the authority of ‘Abdullah ibn ‘Amr ibn al-‘As that the Prophet (PBUH) said:
“ No one should sail on the sea except the one who is going to perform Hajj or ‘Umrah , or the one who is going to fight in Allah's path for under the sea there is a fire , and under the fire there is a sea ” .
Explanation of the Hadith
This honorable hadith coincides with the Qur'anic oath at the beginning of the chapter of at-Tur (The Mount) in which Allah, the Almighty, swears – in spite of the fact that He has no need to swear – by the burning sea. Almighty Allah says:
﴾ By the Mount . And by the Book Inscribed. In parchment unrolled. And by the Bait-ul-Ma'mur (the house over the heavens parallel to the Ka'bah at Makkah, continuously visited by the angles). And by the roof raised high (i.e. the heaven). And by the burning sea. Verily, the Torment of your Lord will surely come to pass. There is none that can avert it. ﴿ (Surat At-Tur (The Mount): 1-8)
When the Ever-Glorious Qur'an was revealed, the Arabs could not perceive the connotation and the meaning of swearing by the burning sea, for the verb "burn" means to destroy or damage by fire. Furthermore, fire and water are bitter enemies as water extinguishes fire and heat vaporizes water. How is it possible then for such opponents to live together? How is it possible for opposites to unite and none of them overpowers the other?
The Arabs then tended to refer the whole matter to the Day of Judgment in the light of what is mentioned at the chapter of at-Takwir (The Folding Up) in which Almighty Allah says :
﴾ And when the seas shall be burnt ﴿ (Surat At-Takwir ( Wound Round and Lost its Light): 6)
However, this is not true, as the verses at the beginning of the chapter of at-Takwir refer to the future events of the Day of Judgment while the oath at the beginning of the chapter of at-Tur refers to realistic events in our life. Therefore, there is no comparison.
This has led a number of interpreters to look for another meaning of the verb "Sajjar" instead of "burn". They were pleased to know that it has another meaning ; "to swell up" , as they are now able to interpret the verse saying that Allah has told humanity that He has filled oceans and seas with water and prevented them from overflowing over land . Actually, this honorable hadith that in this worldly life, there is a fire under the sea and there is a sea under the fire.
The Prophet (PBUH) never sailed over the sea during his lifetime, that so what obliged him to talk about an unseen matter, except that Almighty Allah ordered him to do so. Almighty Allah knew through His Comprehensive Knowledge that someday man would discover this amazing scientific fact, so He mentioned it in the Ever-Glorious Qur'an and informed His honorable Prophet about it so that it would remain a sign asserting that the Ever-Glorious Qur'an is Allah's Words and His final Prophet's words were revealed to him. Allah, the Almighty, says:
﴾ He (Muhammad) does not speak of (his own) desire ﴿ (Surat An-Najm (The Star): 3)
Following World War II , scientists roamed oceans and seas searching for some minerals whose reservoirs were near to be exhausted because of the extravagant materialistic human civilization . They were astonished to find that many volcanic mountain chains extended throughout all oceans along thousands of kilometers and they called them the Mid-ocean Mountains. By studying these oceanic mountain chains, it became clear that they were formed as a result of violent volcanic eruptions through a huge net of deep faults that split the rocky crust and completely surrounded it. These faults were mainly centered on the ocean floor. Also, it became evident that this net of faults extends to more than 64.000 kilometers and their depth reaches about 65 kilometers penetrating the rocky crust and reaching the weak layer known as the zone of weakness (the asthenosphere). In the asthenosphere, the rocks are in a partially molten state with relatively high density and viscosity. The hot currents drive these enormous tons of rocks to the ocean floor and to some sea bottoms such as the Red Sea where the temperature exceeds 1000oC. These rocks are estimated to amount to millions of tons pushing the ocean water to the right and left, in a phenomenon known by scientists as "the phenomenon of expanding and re-forming the sea and ocean floors". The areas resulting form the process of expansion are filled with this magma, which leads to fire on the ocean floors and some sea bottoms.
One of the phenomena that scientists have failed to find an answer to is how the water of oceans and seas cannot put out the magma! Moreover, how is it that this magma, in spite of its extreme temperature, is unable to vaporize seas and oceans?
This balance between the opposites: fire and water on the ocean floors (including the South Atlantic Ocean and the Arctic Ocean), and some sea bottoms, is a clear witness to the Unlimited Power of Allah.
In a project to employ the mineral wealth at the bottom of the Red Sea, where volcanic eruptions violently take place and enrich the sediments of its sea floor, a research ship threw down a metal hook to obtain samples of the clay. When this metal hook got out of the water, no one could touch it because of its extreme heat. When they opened it, they found that the temperature of the clay and hot vapor exceeds 300o C. Therefore, the scientists came to know that the volcanic eruptions in the ocean floors, and some sea bottoms greatly exceed all those found on land. Also, it was proven with clear-cut evidence that Almighty Allah brought out all water from the land. Moreover, the magma in the asthenosphere, and below it, contains a huge amount of water that exceeds all that is found on the surface of the earth.
Thus, we see the magnificence of this honorable hadith in which the Prophet (PBUH) stated and clarified some facts about our planet. Man was only able to reach these facts a few years ago.