Seawater The Prophet b said about the sea: "Its water 1s pure and its dead is allowed (to eat)."
Allah has made the sea salty for the benefit of the people and the animals of the earth. Seawater is plentiful and has sufficient amounts of animals [and fish] that die but do not get buried in it. If the seawater is fresh and sweet, the animals that would die in it would make it rotten, adversely affecting the quality of the air on the earth. Allah's wisdom has decided that seawater is salty, that even if the entire dead corpses produced on the earth were thrown in it, it would still be fresh until Allah brings this world to its inevitable end. This is one of the reasons why seawater is salty, along with its soil and sand In addition being salty.
Taking a bath in seawater helps relieve many illnesses and infections that appear on the skin. Drinking
seawater is harmful, it causes diarrhea, weakens the body and causes rashes, mange and thirst.
Those who have to drink seawater do so for certain medicinal purposes. In this case, seawater should be boiled in a pot that is covered by wool, which will absorb the water vapor. Then, the collected water should be squeezed out of the wool and consumed when there is sufficient amount of it. Meanwhile, the salt and the minerals will remain in the pot.
In addition, one could dig a hole near the seashore to collect the water through several parallel tunnels that would make the water fresh at the end [when it passes through them repeatedly].
If one has to drink seawater, he should first mix it with apricot pips, burning coal, Armenian argil (type of earth), oak wood or fine wheat flour. This way, most of the minerals and mud will be collected in the bottom of the pot or the cup.