Why does he ask who ascended to Shamayim?
Rashi: Who ascended like Moshe did?
Malbim: How can I know Da'as Kedoshim, to know who ascended to Shamayim and descended? His question was about Ma'ase Bereishis - how came about the two Hiyulim (formless matters) from which Shamayim and Eretz were created? Who fixed their borders above and below? Who ascended to Shamayim to bound the depth of the height [of Shamayim], and Who descended to bound the depth of [the land] below?
Which Ru'ach is discussed?
Rashi: This is "Pi'ach ha'Kivshan" (Shemos 9:8; he gathered ashes 1 in his hands, and threw it).
Malbim: The Yesod of Avir - its way is to spread to where there is void. Who gathered it and limited it to stand around the earth, and above [the atmosphere] is not air proper for any living being to breathe? Who gathered it in his hands like this?
Midrash ha'Gadol (Shemos 1:1) expounds this to discuss Aharon, who also gathered ashes; however, Rashi expounds the entire verse about Moshe. Why are ashes called Ru'ach? Rashi (Shemos 9:8) - Pi'ach is fine ashes, which the wind scatters. The other Midrashim, e.g. Bamidbar Rabah (12:11), cite "k'Tzeisi Es ha'Ir Efros Es Kapai" (ibid. 29; he spread his hands in prayer, and stopped Makas Barad, which was via wind). (PF)
What is the meaning of "Mi Tzarar Mayim"?
Rashi: "Kaf'u Sehomos", "Nitzevu Chemo Ned" (Shemos 15:8), via Moshe's Tefilah.
Malbim: The nature of water is to surround the entire earth. Who gathered it in the ocean, and made sand a border for the water, lest it spread past [that border - Yirmeyah 5:22], as if it is wrapped in a garment, and cannot leave?
What is the question "Mi Hekim?
Rashi (citing Pesikta d'Rav Kahana): Who erected the Mishkan? Via it, all ends of the land were founded.
Malbim: Who made the earth's nature to stand in the middle, suspended on nothingness, and all ends of the land are drawn by gravity to the weight in the middle 1 ?
Malbim: The questions pertain to the four 'elements'. Shamayim is the place of fire, like early Chachamim said. After, they pertain to wind, water and the earth, which is Yesod he'Afar.
Why does it ask his name and his son's name?
Rashi: If you will say that there was already someone like this - tell me his son's name! What family came from him, and we will know who he is!
Malbim: The questioner became philosophical - from the First cause, emanated the first outcome (Sechel). It is called a son of the First cause.
Why does it say "Ki Seda"?
Rashi: If you know who it is, how did you not fear to transgress his words?!
Malbim: If you want to know and understand all this via your Sechel and investigation - you cannot know it via human investigation!