The 'fresh and sweet' is the Exoteric Science. The drink which no one finds distasteful or dislikes, but rather drinks and accepts, is the River of Talut.

Talut is the Name (al-Ism), and his river is: the legal exoteric science (al-‘ilm al-zahiri al-shar‘i) with which Allah tested the believers. And His, Mighty and Majestic, saying: {... Indeed, Allah will test you with a river. So whoever drinks from it is not of me, and whoever does not taste it is indeed of me, except one who scoops a handful with his hand. But they drank from it, except a few of them...} (Al-Baqarah 249). Meaning: except he who took according to [the measure] by which he establishes the exoteric (al-zahir) among its people, and it is the permissible knowledge that is commanded. The "fresh meat" and the "ornament" are the reports (al-akhbar) that the believer hears from the People of the Exoteric; thus he is strengthened by them, and his insight into the gnosis (ma‘rifa) of Allah increases.

The "salty and bitter" [sea] is the Esoteric Science (‘ilm al-batin): the bitter, the difficult, the distasteful to the palate, toward which the People of the Exoteric do not incline, except for one whose heart's lock Allah has opened and whom He has guided to His religion.

And I will increase your clarification, O seeker, with the example established for us regarding the "demolishing of the wall"—which is the exemplar (al-mamthul) of the deficiency of the exoteric sciences—and its "restoration" over the "treasure"—which is the exemplar of the