What is the meaning of "k'No'ach
Alshich: When the feet (of those carrying the Aron) rest (touch the water).
Malbim: It is due to the power of the Aron and its Kedushah.
What is the meaning of "Yichrosun"?
Malbim: There will be a division of the water. The water upstream [from the Aron] will pile up, and the water downstream will flow normally.
What is "ha'Mayim ha'Yordim mil'Ma'alah"?
Rashi: This is the way rivers normally flow, from high to low.
What is "va'Ya'amdu Ned Echad"?
Rashi: The water that does not descend will pile up high. "Ned" is like (Tehilim 33:7) "Kones ka'Ned."
Radak: The water will not spread out. It will pile up within the banks of the Yarden.
Malbim: In Keri'as Yam Suf, the water split and formed a Ned (pile) on each side. Here, the water downstream will flow normally, so it will form only one Ned.
