What is "u'le'Chol ha'Yad ha'Chazakah" referring to?
Rashi: It refers to Moshe receiving the (heavy) Luchos 1 with his hands.
Ramban #1: It refers to Keri'as Yam-Suf. 2
Ramban #2 (citing the Sifri): It refers to Makas B'choros. 3
Ramban #3 (according to Kabalah): It refers to the Midas ha'Din. 4
Seforno: It refers to all the miracles that Hashem wrought regarding changing the nature of things that are indestructible - such as the splitting of the Yam-Suf, opening the mouth of the earth bringing down the Manna and others.
Targum Yonasan: It refers to Moshe's staff which weighed forty Sa'ah that Moshe held in his hands and with which he split the Sea and struck the rock.
Rosh (citing a Midrash 5 ): Hashem and Moshe werre both holding two Tefachim of the Luchos, leaving two Tefachim in the middle. After the sin of the Gokden Calf, Hashem wanted Moshe to retain the Luchos, yet He gave Moshe the strength to take them, and he (Moshe) subsequently descended with them.
Yerushalmi Ta'nis, 4:5: It refers to when when after Hashem had Handed the Luchos to Moshe and Yisrael were worshipping the Golden Calf, Hashem made to take back the Luchos, but Moshe overpowered Him, Kevayachol, and snatched them back. 6 That is why the Torah praises Moshe and writes "u'le'Chol ha'Yad ha'Chazakah!'
Sifri (citing R. Elazar): It refers to the wonders of Har Sinai. 7
See Sifsei Chachamim.
Ramban: In connection with which the Torah wrote in Sh'mos, 14:31 "Vayar Yisrael es ha'Yad ha'Gedolah."
Ramban (Ibid.): In connection with which the Torah wrote in Sh'mos, 6:1 - "Ki be'Yad Chazakah Yeshalchem!" See also Torah Temimah, note 28.
Ramban: Like we find in Yechezkel, 37:1 & 40:1 and in Yeshayah, 41:20.
If Hashem wanted to retain them, why did He give Moshe the strength to take them? Perhaps it is similar to "Hanichah Li
What is "u'le'Chol ha'Morah ha'Gadol" referring to?
Rashi: It refers to the miracles and mighty deeds that he performed in the desert. 1
Ramban #1 (citing the Sifri #2), Seforno and Targum Onkelos 2 : It refers to Matan Torah (Ma'amad Har Sinai - Ramban 3 ).
Ramban #2 (citing the Sifri #1): It refers to Keri'as Yam-Suf. 4
Ramban #3 (according to Kabalah): It refers to the Midas ha'Rachamim. 5
Targum Yonasan: It refers to his receiving the sapphire Luchos that weighed forty Sa'ah which he carried (down the mountain) with both hands.
See Torah Temimah, nmote 31.
See 'Shefa Rav'.
Ramban: In connection with which the Torah wrote in Sh'mos, 20:20 "le'Va'avur Tih'yeh Yir'aso al Peneichem".
By which the Torah writes in Sh'mos, 14:30 'Vayir'u ha'Am es Hashem'. See also Torah Temimah, note 29.
Ramban: Like we find in Yeshayah, 8:13. See Ramban DH 've'Al Derech ha'Emes', who equates this explanation with the Sifri - Refer to 34:12:1:3 & 34:12:2:3.
To which incident is "le'Einei Kol Yisrael" referring?
Rashi: It refers to the fact that Moshe's heart inspired him to smash the Luchos 1 before the eyes of all the people. 2
Ramban #1: It refers to Keri'as Yam-Suf and Ma'amad Har Sinai. 3
Ramban (according to Kabalah): He prepared 4 the Yad ha'Chazakah (the Midas ha'Din) and the Mora Gadol (the Midas ha'Rachamim) 5 before the eyes of Yisrael.
Seforno: Refer to 34:12:2:2. It refers to when Yisrael saw and stood at a distance, and Moshe approached the black cloud, where he acquired the highest level of prophecy - "Panim el Panim", 6 and where he became awesome with the Karnei Hod 7 (the rays of majesty).
Targum Yonasan: Refer to 34:12:2:2. It refers to the sapphire Luchos that Moshe brought down the mountain.
Hadar Zekenim: It is emphasising the difference between Moshe and the other Nevi'im. Refer to 34:10:2:8.