1)
What are "Nivchei Yam"?
1.
Rashi: They are closed places of the sea. This is like "Nevuchim Hem ba'Aretz."
2.
Ibn Ezra: They are waves that run, like "mi'Bechi Neharos Chibesh" (28:11).
3.
Malbim: They are the places where water was gathered [to enable the dry land to be seen. Did you go to there?!
2)
What is the significance of "uv'Cheker Tehom His'halachta"?
1.
Malbim: The land stands on the Tehomos (depths). They are hidden from the eye of investigators. Hashgachah is seen doubly there. (a) The waters are gathered there, and do not return to cover the land. (b) Refer to 38:17:2:1.
