What are "Amos ha'Sifim"?
Targum Yonasan: Eilvas Sipei. Rashi - they are the doorposts, which are measured in Amos for height and width, i.e. doorposts of the Heichal. Radak - two or three Amos of the Se'ifim moved.
Radak: Amos are supports on the doorposts from inside and outside, like a dome. They moved with the Sifim.
Malbim: This is a metaphor for Nevi'im, who are depicted as Shomerei ha'Saf - "Tzofeh Nesaticha l'Veis Yisrael" (Yechezkel 3:17). The first responsibility for guilt is on them, for not rebuking and afflicting Yisrael. The verse depicts that the doorposts shuddered due to the noise.
What is "mi'Kol ha'Korei"?
Rashi (from Tanchuma Tzav 13): It is from the voice of the angels who call. This was the "v'Nastem Ka'asher Nastem Mipnei ha'Ra'ash bi'Ymei Uziyah" (Zecharyah 14:5). The day that he stood in the Heichal to burn Ketores, there was great noise in Shamayim to burn him 1 . His law should be "va'Tochal Es ha'Chamishim u'Masayim Ish" (Bamidbar 16:35). This is why he called them Serafim, for they came to burn him. The earth clamored to swallow him, like Korach, who disputed the Kehunah. A Bas Kol (voice from Heaven) said "Zikaron li'Vnei Yisrael" (Bamidbar 17:5) - no one else who will contest Kehunah will be swallowed "k'Korach", or burned "like his congregation." Rather, "Ka'asher Diber Hashem b'Yad Moshe" at the burning bosh - "put your hand in your bosom; he took it out, and it had Tzara'as like snow" (Shemos 4:6). Also here, Tzara'as came on his forehead.
Radak citing Seder Olam: Amos prophesized two years before the noise. Yeshayah prophesized in the days of the noise. However, this verse is a prophetic vision. The voice that he heard angels calling to each other was so great that it moved the doorposts.
What is the significance of the Bayis being filled with smoke?
Radak: The Beis ha'Mikdash was filled with smoke, just like Avraham saw "v'Hinei Tanur Ashan v'Lapid Esh" (Bereishis 15:17). This was a metaphor for the anger against Yisrael, like "Az Yeshan Af Hashem" (Devarim 29:19) [Malbim - and "Alah Ashan b'Apo" (Tehilim 18:9). This is a metaphor for the lower world in general, and Keneses Yisrael in particular.]
