1)
Why is the land called "Nidah"?
1.
Rashi: It is Tamei and repulsive. Malbim - it became Tamei via the Kena'anim's sins - "b'Chol Eleh Nitme'u ha'Goyim...; va'Titma ha'Aretz."
2.
Ibn Ezra: This refers to being distanced.
