"Why should Egypt say" (Exodus 32:12). This is what Scripture says: "This day I have rolled away the reproach of Egypt from you" (Joshua 5:9). Because Pharaoh saw through astrology, and said to Israel, "See, for evil (raah) is before your faces" (Exodus 10:10). He said to them, "I see by my astrology one star rising to meet you, its name is Raah (Evil), and it is a sign of blood and slaughter." And when Israel sinned in the wilderness with the calf, Moses said in his prayer, "Why should Egypt say, For evil (beraah) He brought them out" — this is what we said to you, "See, for evil is before your faces." Immediately, "And the LORD relented of the evil," and He turned the blood into the blood of circumcision, for Joshua circumcised them. And this is what is said, "This day I have rolled away the reproach of Egypt," for they had been saying, "We see blood upon you."
The Star Named Evil Turned Into the Blood of Circumcision
Yalkut Shimoni on Torah 392:6
לָמָּה יֹאמְרוּ מִצְרַיִם. זֶה שֶׁאָמַר הַכָּתוּב (יהושע ה, ט) "הַיּוֹם גַּלּוֹתִי אֶת חֶרְפַּת מִצְרַיִם". לְפִי שֶׁרָאָה פַּרְעֹה בְּאִצְטַגְנִינוּת, וְאָמַר לָהֶם לְיִשְׂרָאֵל, "רְאוּ כִּי רָעָה נֶגֶד פְּנֵיכֶם", אָמַר לָהֶם, אֲנִי רוֹאֶה בְּאִצְטַגְנִינוּת שֶׁלִּי כּוֹכַב אֶחָד עוֹלֶה לִקְרָאתְכֶם, שְׁמוֹ רָעָה וְהוּא סִימַן דָּם וַהֲרִיגָה, וּכְשֶׁחָטְאוּ יִשְׂרָאֵל בַּמִּדְבָּר בָּעֵגֶל אָמַר מֹשֶׁה בִּתְפִלָּתוֹ, לָמָּה יֹאמְרוּ מִצְרַיִם לֵאמֹר בְּרָעָה הוֹצִיאָם, זֶהוּ שֶׁאָמַרְנוּ לָכֶם "רְאוּ כִּי רָעָה נֶגֶד פְּנֵיכֶם", מִיָּד וַיִּנָּחֶם ה' עַל הָרָעָה, וְהָפַךְ אֶת הַדָּם לְדַם מִילָה, שֶׁמָּל אוֹתָם יְהוֹשֻׁעַ, וְזֶהוּ שֶׁנֶּאֱמַר "הַיּוֹם גַּלּוֹתִי אֶת חֶרְפַּת מִצְרַיִם", שֶׁהָיוּ אוֹמְרִים דָּם אָנוּ רוֹאִים עֲלֵיכֶם.