BS"D
After the Sin of the Golden Calf, Moshe calls for Bnei Yisrael to make a decision. He asks them to stand up for the sake of G-d’s Honor, and take up arms to defend His Name. When commanding those who came forward (32:27), Moshe begins the instructions by saying, “Koh amar Hashem Elokei Yisrael- So said Hashem the God of Israel...” This is the only instance where Moshe, when addressing the Jewish People, uses the phrase, “Hashem the G-d of Israel.” Why here and no other place in the entire Torah?
By examining the context of his remarks, I think we can begin to understand why this phrase is employed. Moshe comes down the mountain in furious anger. He proceeds to break the luchos,and confronts the Bnei Yisrael and his brother, Aharon. Moshe, acting as a barometer of the Divine attitude towards the Jews (see Shemoneh Perakim of Rambam for further elaboration of this idea), is clearly demonstrating Divine displeasure. However, even under these trying and tragic circumstances, Moshe is quick to point out that Hashem is still “G-d of Israel.” The newly formed relationship persists in spite of the betrayal. The covenant of commitment forged by the giving of the Torah faces its first serious challenge, and it survives…until this very day.
Have a great Shabbos.