When did Hashem cleave springs and rivers?
Rashi: Hashem cleaved the rock 1 , and springs came out for Yisrael. Radak - it says Mayan based on the end; He cleaved the rock, and it became a spring. We find similarly "Afisi Al Gechalav Lechem", "v'Tachani Kemach" (Yeshayah 44:19, 47:2). One bakes dough, and grinds wheat - in the end, they are bread and flour. It says "Yevaka Tzurim ba'Midbar" (78:15).
We find that Hashem gave water for Yisrael from a rock (Bamidbar 20:11, Devarim 8:15), but it is not explicit there that He cleaved the rock. (PF)
What rivers did Hashem dry?
Rashi: He dried the Yarden, which is Eisan (a mighty river). Radak - the Yarden was in its strength, overflowing its banks, and He dried it for Yisrael to pass. It says Naharos (plural) because other rivers flow into the Yarden. Eisan is a noun, and not an adjective; Naharos is Samuch to it.
Why does it put together cleaving springs and drying rivers?
Radak, Malbim: He does opposites. He turns a rock into a spring, and dries a river! Malbim - also below, it says "Mah Lecha ha'Yam Ki Sanus; ha'Hofchi ha'Tzur Agam Mayim" (114:5, 8).
