1)
Why does it say "Ki me'Al Kol ha'Am Hayah"?
1.
Rashi: Therefore, everyone saw him.
2)
What is the meaning of "uch'Fischo Amdu Kol ha'Am"?
1.
Rashi, Ibn Ezra #1, from Sotah 39: When he began to read, everyone was silent. Amdu is an expression of silence, like "Amdu v'Lo Anu Od."
2.
Ibn Ezra #2: Perhaps they stood to honor the Torah - "va'Yakumu Al Omdam." It says in Megilah (21a), from the days of Moshe until R. Gamliel, people used to learn while standing.
