What do we learn from "Mah she'Hayah Hu she'Yihyeh"?
Rav Sadya Gaon: What came about in the past, it will be in the future. Rashbam - therefore, "Mah Yisron
Yehoshua made the sun stand still, and the Yarden piled up when Yisrael crossed. Midrash Tanchuma (Tetzaveh 9) says that also Moshe made the sun stand still, and water stood at Keri'as Yam Suf (although not as tall as the Yarden). Prophets and Amora'im revived the dead - this already occurred at Matan Torah! Elisha made metal float - Moshe caused Yosef's metal coffin to float (Sechel Tov Shemos 13:19). Lions did not eat Daniel - lions in Pharaoh's palace were docile when Moshe entered (Pesikta Zutresa Shemos 4:22). A wind took Eliyahu to Shamayim, a fish swallowed Yonah and he survived, a man was able to nurse his son (Shabbos 53b)
What do we learn from "Mah she'Na'asah Hu she'Ye'aseh"?
Rav Sadya Gaon: What was done in the past, it will be done in the future.
Metzudas David: The matter is repeated in different words.
What is the consequence of "v'Ein Kol Chadash Tachas ha'Shamesh"?
Shabbos 30b: Also in the future, nothing new will occur. R. Gamliel taught that in the future, women will give birth every day -- "Harah v'Yoledes Yachdav." A Talmid jeered "v'Ein Kol Chadash Tachas ha'Shamesh"! R. Gamliel replied, even today, hens [lay eggs every day 1 ].
Rashi: However, one who thinks about Torah always finds new reasons. "Dadeha Yeravucha b'Chol Es" (Mishlei 5:19) - just like a baby always gets taste from the breast, so are Divrei Torah. We find that R. Elazar said matters about Ma'ase Merkavah that no one ever heard (Chagigah 14b).
Rid: Since nothing new will come about, there is no gain from one's toil, Metzudas David (10).
Metzudas David, Metzudas Tziyon: Nothing is new where the sun shines, i.e. the entire world. Just like no one attained his hope via toil, this will always be! Kol [Chadash] is any [new matter], just like "Lo Sa'aseh Kol Melachah" (Shemos 20:10).
How could he answer for "v'Gar Ze'ev Im Keves
