Rashi on Numbers 34:6/רש"י על במדבר ל״ד:ו׳

1ים וגבול These words (apparently unconnected with what follows) mean: AND THE WESTERN BOUNDARY, what forms that?

2והיה לכם הים הגדול THE GREAT SEA SHALL BE UNTO YOU for the boundary.

3וגבול AND THE BOUNDARY — the נסין which are in the sea also belong to the boundary; they are what are called isles in O. F. (Gittin 8a).