וּגְב֣וּל יָ֔ם וְהָיָ֥ה לָכֶ֛ם הַיָּ֥ם הַגָּד֖וֹל וּגְב֑וּל זֶֽה־יִהְיֶ֥ה לָכֶ֖ם גְּב֥וּל יָֽם׃
And for the western border, ye shall have the Great Sea for a border; this shall be your west border.
Rashi on Numbers
ים וגבול These words (apparently unconnected with what follows) mean: AND THE WESTERN BOUNDARY, what forms that?
Rashbam on Numbers
וגבול ים, as if the Torah had written an introductory line: “how was the westerly boundary?” [clearly, it is difficult to justify these two words. Ed.]
Rabbeinu Bahya
הים הגדול, “the Mediterranean,” known in the author’s time as “the Spanish Sea.” וגבול¸”and the western boundary.” The sea itself is the boundary. (Ibn Ezra).