The two seas: the sweet and the salty are examples of the believer and the disbeliever. Then he said, as a digression regarding the description of the two seas and the blessings and gifts associated with them: 'And from each of them you eat fresh meat,' which is fish, 'and you extract from them ornaments,' which are pearls and coral. 'And you see the ships in it,' in every current, longing for the water by their flow. It is said: 'The ship has plowed the water.' And it is said about the clouds: 'Daughters of plowing,' because they plow the air, and the ship, from which the word 'ship' is derived, is close to 'plowing,' because it plows the water as if it is peeling it, as it plows it from the bounty of Allah. It was not mentioned in the verse, but in what preceded it. And if it had not been mentioned, it would not have been a problem, due to the indication of the meaning upon it. The word of hope is borrowed for the meaning of intention. Do you not see how it has taken the path of the letter of reason, as if it were said: 'So that you may seek' and 'So that you may be grateful'? The Euphrates is that which quenches thirst. The palatable is that which is easy to descend due to its sweetness. It was read: 'Saygh,' with the weight of 'Sayyid,' and 'Saygh' with the lightening. And salty is on the form of 'fa'il.'

And the bitter is that which burns with its salinity. It is possible to interpret it in a different way than the digression: that the two kinds are compared to the two seas, and then the bitter sea is preferred over the disbeliever, because it has shared with the sweet in benefits of fish and pearls, and the ships have flowed in it, while the disbeliever is devoid of benefit. This is in the context of Allah's saying: 'Then your hearts became hard after that, so they are like stones or even harder.' Then he said: 'And indeed, from the stones are those from which rivers burst forth, and indeed, from them are those which split open so that water comes out of them, and indeed, from them are those which fall down out of the fear of Allah.'