We can add, that we find a similar idea in the Possuk a little later in the Parsha: וַׁיוֹרֵהוּ ה עֵץ וַׁיַׁשְּלֵךְ אֶל־הַׁמַׁיִם וַׁיִמְּתְּקוּ הַׁמָיִם and HaShem instructed him concerning a piece of wood, which he cast into the water, and the water became sweet, and it is brought down in the Medrash that this piece of wood was of a species called רְּדוּפְּנִי which is a bitter wood and its fruit is deadly poisonous, yet nevertheless it is specifically this bitter wood which makes the water sweet.
As explained once, that this is not due to a Divine revelation of holy light, but it is due to a transformation of the Sitra Achra, the antithesis of holiness itself. This can be transformed into holiness due to its lofty source in the world of ‘Tohu’.
And this means that it is specifically this bitter Redufni wood, the epitome of bitterness that arouses an awakening to reveal its root in the world of ‘Tohu’, which is the one that sweetens the bitter waters, which is the concept of ‘transformation of darkness into light’ and ‘bitterness into sweetness’, so that the darkness and the bitterness themselves become light and sweetness.
