Shemot 3:6

וַיֹּ֗אמֶר אָנֹכִי֙ אֱלֹהֵ֣י אָבִ֔יךָ אֱלֹהֵ֧י אַבְרָהָ֛ם אֱלֹהֵ֥י יִצְחָ֖ק וֵאלֹהֵ֣י יַעֲקֹ֑ב וַיַּסְתֵּ֤ר מֹשֶׁה֙ פָּנָ֔יו כִּ֣י יָרֵ֔א מֵהַבִּ֖יט אֶל־הָאֱלֹהִֽים׃ and continued, “I am the God of your father’s [house]—the God of Abraham, the God of Isaac, and the God of Jacob.” And Moses hid his face, for he was afraid to look at God.

God speaks to moses. Moses coers his face because he is scared of god. The peak of this event is when god reveals himself. "I am god. The god of…". Reminding him of the covenant of pieces. By mentioning moses' forefathers, he verifies the covenants existence. Moses understands this event's greatness → he covers his face out of fear and respect.Moses now understand this sutation. He knows this is a unique event that deals with the covenant between god and the Jewish nation