Why did Moshe wait until he came close to the camp and actually witnessed the scene before smashing the Luchos?
Yerushalmi Ta'anis, 4:5: This teaches us one may not judge based on assumption alone. 1
Refer to 31:15:1:1-5.
See Torah Temimah, note 35.
What did Moshe see that Hashem had not already told him?
Oznayim la'Torah: This can be explained in a number of ways: 1. The principle 'Eino Domeh Shemi'ah li'Re'iyah'; 2. the joy with which they served the Eigel; 1 3. That they did not greet him upon his return with the same joy with which they served the Eigel - but continued to prance around it as before. 2
Oznayim la'Torah: Perhaps Moshe's anger can be attributed to the fact that they served the Eigel with a joy that they did not display when serving Hashem.
A proof that their claim that they wanted someone to replace Moshe was merely an excuse to worship idols. Refer also to Devarim, 9:16 for more details.
On what grounds did Moshe break the Luchos?
Rashi #1 (citing Shabbos, 87a): He Darshaned a Kal va'Chomer from the Korban Pesach (which is only one Mitzvah), in which the Torah prohibits a ben Neichar 1 (an idolater) from participating; How much more so may the Luchos (which contain the entire Torah) not be given to Yisrael, who were apostates.
Rashi #2 (on 34:1): In order to put forward the argument that Yisrael were not betrothed to Hakadosh-Baruch-Hu, 2 thereby lightening their guilt.
Ramban #1 (on Pasuk 16): Because when he saw Yisrael worshipping the Golden Calf, his anger flared up 3 and he was unable to restrain himself. 4
Ramban #2 (Ibid., citing Midrash Rabah): He broke the Luchos when he arrived in the vicinity of the Golden Calf and the letters flew from them. 5
Rashbam: When he saw the Eigel he became weak and was no longer able to hold the Luchos. 6
Seforno: When he saw them (not just worshipping the Golden Calf, but) dancing and rejoicing over it, 7 he realized that there was no chance of their doing Teshuvah. 8
Targum Yonasan: 'When Moshe saw the Eigel, the Resha'im playing the tambourines and prostrating themselves before it and the Satan leaping and dancing before the people, his anger flared-up. 9
Oznayim la'Torah: He brought down the Luchos in the hope that, when the people saw them, they would do Teshuvah. 10 however, when he saw how they were indulging in Avodah Zarah, Giluy Arayos and Shefichus Damim and the extent of their Simchah, 11 he realized that they had completely removed the yoke of Torah and Derech Eretz and that the only way of achieving that goal was via shock treatment - by smashing the Luchos before their eyes.
See 12:43.
Refer to 34:1:3:1*. Despite the fact that they had already received the Torah - See Oznayim la'Torah.
The Pasuk specifically attributes Moshe's subsequent reaction to his anger.
According to Targum Yonasan, the letters flew from the Luchos after Moshe broke them.
Bear in mind that they weighed forty Sa'ah (Targum Yonasan 31:18). He did not just drop them; he cast them away, to prevent them from falling on his feet (Rashbam and Moshav Zekenim).
See Targum Yonasan who also stresses the rejoicing element of both the people and the Satan, who had joined them.
And he proclaimed 'Woe to rhe people who heard on Sinai from the Mouth of Hakadosh-Baruch-Hu 'Do not make for yourselves an idol, an image or any form, and after forty days they made a metal calf that has no substance!' (Targum Yonasan).
What is the connotations of "Tachas ha'Har"?
Rashi, Targum Onkelos and Targum Yonasan: It means 'at the foot of the mountain'. 1
See Sifsei Chachamim.
Since Hashem approved of Moshe breaking the Luchos, why didn't He tell him to leave them in the heaven (on the mountain)?
Moshav Zekenim #1: Because since Hashem had already given them to Moshe, he could not delay giving them, since "Lo Ish Keil Viyechazev" (Bamidbar 23:19).
Moshav Zekenim #2: there was no reason why the tribe of Levi should not receive them, since none of them had sinned. 1
The question then remains why Moshe did not give the tribe of Levi the Luchos.
Why did Moshe break the Luchos and not hide them, so that, should Yisrael repent, he could give them to them then? Even after the letters departed, they still had Kedushah (just like a Seifer Torah that has been erased); the broken Luchos were placed in the Aron Kodesh?
Refer to 32:19:151:1-2.
Moshav Zekenim #1: He took them down, because he thought that only the Erev Rav were sinning. When he saw that Yisrael were sinning too, he cast them down in order to get there quickly and stop them. 1
Moshav Zekenim #3: He broke them in order to make Shalom between Yisrael and Hashem (to prevent them from being guilty of sinning 2 - Refer to 32:19:2:2.
Refer to 32:19:2:8.
Moshav Zekenim (citing R. Yehudah ha'Chasid): This teaches us that if one is carrying a Seifer Torah and sees people who want to sin, if necessary, he may throw it down in order to run quicker to stop them. Normally, one does not sin to bring merit to others, but a communal Mitzvah is different.
If s Kohen can erase Hashem's name (by a Sotah) to make Shalom between a man and his wife, how much more so here. The Gemars in Yevamos 62a however, implies that Mosh broke the Luchos because Yisrael were not worthy to receive them.
QUESTIONS ON RASHI
Rashi writes that Moshe broke the Luchos due to a Kal va'Chomer. But the Gemara in Yevamos 62a states that Moshe himself decided to break them?
Riva and Moshav Zekenim: Because the Kal ve'Chomer was flawed, 1 in that on the one hand an idolater may not eat the Korban Pesach since it is a Korban, but on the other, he should receive Torah, to enaable him to repent.
The Gemara in Shabbos, 87a actually equates 'of his own accord ('mi'Da'ato') with the Kal va'Chomer, and Tosfos there queries the contradiction in terms.. See Torah Temimah, citing Shabbos, Ibid. and note 36.