Why does the Torah repeat "Vaya'amod ha'Am me'Rachok"?
Targum Yonasan: To teach us that they remained standing twelve Mil from Har Sinai. 1
In spite of Moshe's reassurance (Oznayim la'Torah). And they remained there until angels came and escorted them back. Refer to 20:15:5:1**.
Where did Moshe go?
Rashi: He went to within the three Mechitzos - Choshech, Anan and Arafel. 1
Ramban: Refer to 20:15:4:2***********
Rashi: Which was equivalent to the "Av he'Anan" mentioned earlier in 19:9. See also Ba'al ha'Turim.
Why does the Torah write "u'Moshe Nigash" (Hif'il), and not 'Gash'?
Moshav Zekenim (citing Pirkei d'R. Eliezer (in Pasuk 41): Because Micha'el and Gavriel forced him to come close, against his will.
Why was the Torah given amidst darkness and not amidst light?
Hadar Zekenim: Hashem knew that they will serve idolatry, so He did not give it amidst light, in order not to increase the Simchah (and with t, the impact of the sin).