At Marah, where the water was too bitter to drink, Targum Pseudo-Jonathan tells us what the Hebrew only hints at. Moses prayed, and the Lord showed him the bitter tree of Ardiphne, and he wrote upon it the great and glorious Name, and cast it into the midst of the waters, and the waters were rendered sweet.
The Ardiphne is the oleander, a tree whose sap is poisonous and whose name in Aramaic already carries the taste of bitterness. The Targumist is making a pointed observation: the remedy for the bitter water was not a sweet tree. It was a bitter tree, inscribed with the Name.
Think about the logic. If you wanted to sweeten water, you would throw in honey, or dates, or sugar cane. You would not throw in oleander. The Targum is saying that the transformation happened not through the addition of sweetness but through the writing of the Shem ha-Meforash, the Explicit Name of God. The bitterness of the tree was irrelevant. The Name did the work.
The Targum then adds that at Marah, the Word of the Lord gave Israel three statutes: the ordinance of the Sabbath, the statute of honoring father and mother, and the laws of civil damages. Three commandments, before Sinai. The Sages located these three at Marah because the Hebrew says God set for them a statute and an ordinance there.
The Maggid draws the parallel. The bitter tree sweetened the water because the Name was on it. The bitter wilderness was sweetened for Israel because the first commandments were given in it. Both transformations work the same way. Bitterness plus Torah equals sweetness. Bitterness alone equals death.