Allah says:

{And had We willed, We would have raised a warner in every town.} (25:51)

‘Calling them to Allah, but We have singled you out, O Muhammad, to be sent to all the people of earth, and We have commanded you to convey the Qur’an,’

{that I may therewith warn you and whomsoever it may reach} (6:19).

{but those of the sects that reject it, the Fire will be their promised meeting place} (11:17).

{that you may warn the Mother of the Towns and all around it} (42:7).

{Say: "O mankind! Verily, I am sent to you all as the Messenger of Allah..."} (7:158).

In the Two Sahihs (it is reported that the Prophet said:)

«I have been sent to the red and the black .» And:

«A Prophet would be sent to his own people, but I have been sent to all of mankind.»

Allah says:

meaning, with the Qur’an. This was the view of Ibn ‘Abbas.

{with the utmost endeavour.} This is like the Ayah,

{O Prophet! Strive hard against the disbelievers and the hypocrites,} (9:73)

means, He has created the two kinds of water, sweet and salty. The sweet water is like that in rivers, springs and wells, which is fresh, sweet, palatable water. This was the view of Ibn Jurayj and of Ibn Jarir, and this is the meaning without a doubt, for nowhere in creation is there a sea which is fresh and sweet.

Allah has told us about reality so that His servants may realize His blessings to them and give thanks to Him. The sweet water is that which flows amidst people. Allah has portioned it out among His creatures according to their needs; rivers and springs in every land, according to what they need for themselves and their lands.

{and that is salty and bitter;} meaning that it is salty, bitter and not easy to swallow. This is like the seas that are known in the east and the west, the Atlantic Ocean and the Straits that lead to it, the Red Sea, the Arabian Sea, the Persian Gulf, the China Sea, the Indian Ocean, the Mediterranean Sea, the Black Sea and so on, all the seas that are stable and do not flow, but they swell and surge in the winter and when the winds are strong, and they have tides that ebb and flow. At the beginning of each month the tides ebb and flood, and when the month starts to wane they retreat until they go back to where they started. When the crescent of the following month appears, the tide begins to ebb again until the fourteenth of the month, then it decreases. Allah, may He be glorified, the One Whose power is absolute, has set these laws in motion, so all of these seas are stationary, and He has made their water salty lest the air turn putrid because of them and the whole earth turn rotten as a result, and lest the earth spoil because of the animals dying on it. Because its water is salty, its air is healthy and its dead are good (to eat), hence when the Messenger of Allah was asked whether sea water can be used for Wudu’, he said:

«Its water is pure and its dead are lawful.»

This was recorded by Malik, Ash-Shafi'i and Ahmad, and by the scholars of Sunan with a good [ Jayyid ] chain of narration.

meaning, between the sweet water and the saltwater.

{a barrier} means a partition, which is dry land.

in the beginning, he is someone’s child, then he gets married and becomes a son-in-law, then he himself has sons-in-law and other relatives through marriage. All of this comes from a despised liquid, Allah says: