"And the two daughters of Lot conceived by their father" (Genesis 19:36) - they took control of themselves and exposed their own nakedness. Rabbi Nachman bar Chanin said: anyone who is greedy after the ravenous hunger for forbidden relations, in the end they feed him from his own flesh. We do not know whether Lot desired his daughters or whether his daughters desired him; from what is written, "He who separates himself seeks his own desire" (Proverbs 18:1), it follows that Lot desired his daughters, and his daughters did not desire him. There is no Sabbath [another version: no year] on which the portion of Lot is not read. What is the reason? As it is written, "in all sound wisdom he breaks out" (yitgala, Proverbs 18:1). It is not written "they broke out" (in the plural), but "he breaks out" - the men were distanced, but the women were brought near. This is what is written, "I know, declares the LORD, his arrogance, and the falseness of his boasts" (Jeremiah 48:30). Rabbi Huna bar Pappa and Rabbi Simon [differed]. Rabbi Huna said: the beginning of Moab's conception was not for the sake of harlotry but for the sake of Heaven; "his boasts" [the later Moabites] did not act so for the sake of Heaven but for the sake of harlotry, as it is said, "and the people began to commit harlotry with the daughters of Moab" (Numbers 25:1).
Both Daughters of Lot Conceived From Their Father
Yalkut Shimoni on Torah 86:4
(בראשית יט לו) וַתַּהֲרֶיןָ שְׁתֵּי בְנוֹת לוֹט, שָׁלְטוּ בְּעַצְמָן וְהוֹצִיאוּ עֶרְוָתָן. אָמַר רַבִּי נַחְמָן בַּר חַנִין, כָּל מִי שֶׁהוּא לָהוּט אַחַר בּוּלְמוּס שֶׁל עֲרָיוֹת סוֹף מַאֲכִילִין אוֹתוֹ מִבְּשָׂרוֹ אֵין אָנוּ יוֹדְעִים אִם לוֹט נִתְאַוָּה לִבְנוֹתָיו אוֹ אִם בְּנוֹתָיו נִתְאַוּוּ לוֹ, מִמַּה דִּכְתִיב (משלי יח, א) "לְתַאֲוָה יְבַקֵּשׁ נִפְרָד" הֱוֵי לוֹט נִתְאַוָּה לִבְנוֹתָיו וּבְנוֹתָיו לֹא נִתְאַוּוּ לוֹ. אֵין לְךָ כָּל שַׁבָּת וְשַׁבָּת [נ"א שָׁנָה וְשָׁנָה] שֶׁאֵין קוֹרִין בָּה פָּרָשָׁתוֹ שֶׁל לוֹט, מַאי טַעֲמָא, דִּכְתִיב, (שם) "בְּכָל תּוּשִׁיָּה יִתְגַּלָּע" הִתְגַלְּעוּ אֵין כְּתִיב כָּאן, אֶלָּא "יִתְגַּלָּע" אֲנָשִׁים נִתְרַחֲקוּ וְנָשִׁים נִתְקָרְבוּ. הֲדָא הוּא דִּכְתִיב, (ירמיה מח, ל) אֲנִי יָדַעְתִי וְגוֹ' עֶבְרָתוֹ וְלֹא כֵן בַּדָּיו רַבִּי הוּנָא בַּר פָּפָּא וְרַבִּי סִימוֹן, רַבִּי הוּנָא אָמַר תְּחִלַּת עִבּוּרוֹ שֶׁל מוֹאָב לֹא הָיָה לְשֵׁם זְנוּת, אֶלָּא לְשֵׁם שָׁמַיִם "בַּדָּיו" לֹא עָשׂוּ כֵּן לְשֵׁם שָׁמַיִם אֶלָּא לְשֵׁם זְנוּת, שֶׁנֶּאֱמַר, "וַיָּחֶל הָעָם לִזְנוֹת אֶל בְּנוֹת מוֹאָב".