d2517d7b_on__Book_Exploring_The_Qur_an___on_Revealed_in_The_Holy_Qur_an
There is no man-made theory. Some speculate that it came from comets (huge bodies of ice and dust that moves with great speeds in outer space) which impacted on the earth.
How did water come to the earth? During the last four thousand lunar years of the creation, ALLAH (SWT) Made the solid foundations (tectonic plates) on top of the inner part of the earth (which was created in the first two thousand lunar years of the creation). Also during this period ALLAH (SWT) Has Placed all the earth's resources (including water) within its crust. As the earth started to spin, the stresses due the spinning motion caused the earth's crust to crack at many locations. Water exited from within the earth's crust to the surface.
Islam: Creation, Science, Miracle, Quran & Religion. Book Exploring The Qur'an.
Phenomenon Revealed in The Holy Qur'an