What is the significance of "Elohei Masechah Lo Sa'aseh lach" here?
Hadar Zekenim and Da'as Zekenim: Following the sin of the Eigel, Hashem is warning them not to indulge in such stupidity again.
Erech Apayim (1, based on the Zohar Tetzaveh, 182:2): It is a warning against making an idoatry through anger, since it causes the Holy Neshamah to depart..
Why does the Torah need to insert the current Pasuk? Why would we have thought that they are permitted?
Seforno: It is a prohibition against turning to a molten idol for financial and personal gains 1 - without actually accepting them as gods. 2
See Seforno, who describes the procedure.
Whereas the Torah expects us to turn to Hashem and to Hashem alone for all our needs, as the Pasuk indicates in Divrei ha'Yamim 2, 2:12 (Seforno).
