What is "b'Sha'alo"?
Rashi: In His going - "Darachta va'Yam Susecha" (Chabakuk 3:15).
Radak: It is His fist. This is a metaphor, for Hashem does not have a hand or fist.
What do we learn from "Mi Madad b'Sha'alo Mayim"?
Radak: The nations should not be astounded if I take Yisrael from their service. They were under their jurisdiction for many years. The One who created the world from nothing, He can do this! The water is in a Mikveh (gathered place), like one who measures water and puts it in a Kli, to know its measure. So Hashem put water in its place and knows its measure.
What do we learn from "v'Shamayim ba'Zeres Tiken"?
Eruvin 21a: From here we learn Torah's measure. "Megilah Afah Arkah Esrim ba'Amah v'Rachbah Eser ba'Amah" (Zecharyah 5:2; this refers to Hashem's Amah). "Afah" is folded; unfolded, it is 20 by 20 Amos. Torah was written on it "Panim v'Achor"; on one side, it would be 40 by 20. Our verse teaches that the Torah is like Hashem's Zeres (half an Amah. the Torah is 80 times as long and 40 times as wide, i.e. 3,200 times the size of the world.
Rashi: Tiken is measuring or counting, like "v'Sochen Levenim Titenu" (Shemos 5:18).
Radak: Something spread, like Shamayim, is measured via Zeres and Kanah (a stick). It says Tiken, for what is spread must be adjusted - "va'Yimtachem ka'Ohel Lashaves" (22).
What is the meaning of "v'Chol ba'Shalish Afar ha'Aretz"?
Rashi #1: He measured [and divided] into thirds - a third [of the world] is Midbar, a third is settled, and a third is seas and rivers.
Rashi #2: From the thumb until the Amah (index finger), the third finger.
Rashi citing Menachem: Shalish is the name of a Kli - "va'Tashkemo bi'Dma'os Shalish" (Tehilim 80:6).
Radak: V'Chol means "He measured." The Targum of "va'Yamodu va'Omer" (Shemos 16:18) is u'Chlu v'Umra. Shalish is a large measure - "va'Tashkemo bi'Dma'os Shalish." It is as if He measured the soil.
Why does it say "v'Shakal ba'Peles Harim"?
Rashi: Everything is according to the land. A heavy mountain He inserted in hard land, and a light [mountain] in soft land.
Radak: Peles is an iron rod with dots to indicate the weight. He created everything in the proper measure - "va'Yar Elokim Es Kol Asher Asah v'Hine Tov Me'od" (Bereishis 1:31).
Malbim: He weighed the great mountains, and also the small hills, so they will correspond to each other.
What is the significance of the matters mentioned in this verse?
Rashi: Hashem did all these - all the more so He has power to guard these promises!
Radak #1: They are three of the four 'elements'. Shamayim is in place of fire. Wind was not mentioned, for it is not seen, even though it is felt. The verse addresses fools who believe only what they see.
Radak #2: All the four 'elements' are mentioned; wind is in verse 13 "Mi Siken Es Ru'ach Hashem." Hashem is not Samuch to Ru'ach; rather, it answers the question "who established Ru'ach?" (Hashem did.)
Radak #3: All the four 'elements' are mentioned; Shamayim hints to fire and air. Three of them are Samuch to (measured via) Hashem Himself, i.e. b'Sha'alo and ba'Zeres, for they are above. Even though water is below, sometimes it ascends in clouds.
Malbim: This refers back to verse 10 - He will come with strength. How can you say that He lacks ability to fulfill His promise!? He measured water in His measure, and prepared Shamayim (fire) with His Zeres and finger. He measured the soil, and arranged the weight of the earth lest it falter from the middle of the spheres that surround it.