Midrash for Daniel 10:20
וַיֹּ֗אמֶר הֲיָדַ֙עְתָּ֙ לָמָּה־בָּ֣אתִי אֵלֶ֔יךָ וְעַתָּ֣ה אָשׁ֔וּב לְהִלָּחֵ֖ם עִם־שַׂ֣ר פָּרָ֑ס וַאֲנִ֣י יוֹצֵ֔א וְהִנֵּ֥ה שַׂר־יָוָ֖ן בָּֽא׃
Then said he: Knowest thou wherefore I come unto thee? and now will I return to fight with the prince of Persia; and when I go forth, lo, the prince of Greece shall come.
Sifrei Devarim
"and there was no strange god against them": None of the nations will be permitted to come and rule over you, as it is written (Daniel 10:20) "Then I will depart. And, behold, the (tutelary) power of Greece approaches" (Ibid. 10) "But the power of Persia stood opposed to me," (Ibid. 21) "But I will tell you what is inscribed in truthful writing, etc."
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