Who says "Bo'u Nishtachaveh"?
Radak: One will say so to his colleague, for we are obligated to thank Him and bow to Him all kinds of bowing. "Nishtachaveh" is spreading out the entire body on the ground, including hands and feet.
Malbim: Yisrael. We do not recognize Hashem first via His general deeds, rather, because He made us a nation. He did special benefits for us.
What is "Nichre'ah"?
Rashi: It is an expression of kneeling, like "va'Yavrech Es ha'Gemalim" (Bereishis 24:11).
Radak: It is bowing the knees on the ground, like "va'Yichra Al Birkav" (Melachim II, 1:13).
Why does it say "[Lifnei Hashem] Osenu"?
Radak: He aggrandizes us and elevates us. This is like "Asher Asah Es Moshe v'Es Aharon" (Shmuel I, 12:6).
Malbim (4): Nations understand Hashem - from His general deeds. We bow to Him for He is our G-d, and we are His flock (verse 7) - i.e. due to His special deeds for us.
