Reference for Avodah Zarah 3:5
הַגּוֹיִם הָעוֹבְדִים אֶת הֶהָרִים וְאֶת הַגְּבָעוֹת, הֵן מֻתָּרִין וּמַה שֶּׁעֲלֵיהֶם אֲסוּרִים, שֶׁנֶּאֱמַר (דברים ז) לֹא תַחְמֹד כֶּסֶף וְזָהָב עֲלֵיהֶם וְלָקַחְתָּ. רַבִּי יוֹסֵי הַגְּלִילִי אוֹמֵר, (שם יב) אֱלֹהֵיהֶם עַל הֶהָרִים, וְלֹא הֶהָרִים אֱלֹהֵיהֶם. אֱלֹהֵיהֶם עַל הַגְּבָעוֹת, וְלֹא הַגְּבָעוֹת אֱלֹהֵיהֶם. וּמִפְּנֵי מָה אֲשֵׁרָה אֲסוּרָה, מִפְּנֵי שֶׁיֶּשׁ בָּהּ תְּפִיסַת יָד אָדָם, וְכֹל שֶׁיֶּשׁ בָּהּ תְּפִיסַת יְדֵי אָדָם אָסוּר. אָמַר רַבִּי עֲקִיבָא, אֲנִי אוֹבִין וְאָדוּן לְפָנֶיךָ. כָּל מָקוֹם שֶׁאַתָּה מוֹצֵא הַר גָּבוֹהַּ וְגִבְעָה נִשָּׂאָה וְעֵץ רַעֲנָן, דַּע שֶׁיֶּשׁ שָׁם עֲבוֹדָה זָרָה:
The gentiles who worship the mountains and the hills — they [the mountains themselves] are permitted [for sowing and for hewing stones from them, what is rooted, not being forbidden]; and what is upon them is forbidden. As it is written (Deuteronomy 8:25): "You shall not covet the silver and gold upon them and take it." R. Yossi Haglili says (Ibid. 12:2): "Destroy shall you destroy… their gods upon the mountains"; but the mountains (themselves) are not their gods. "their gods upon the hills"; but the hills (themselves) are not their gods. Why, then, is an asheirah (a tree devoted to idolatry) forbidden? [That is, just as we expound "their gods upon the mountains"; but the mountains themselves are not their gods, we can expound (Ibid.): "their gods are under every leafy tree"; but the leafy tree (itself) is not their god!] Why, then, does the Torah forbid (derivation of benefit from) it, it being written (Ibid. 7:5): "And their asheirah trees shall you cut down"?] Because a man's hands have a "hold" in it. [i.e., because a man's hands planted it, (R. Yossi holding that a tree planted by a man and then worshiped by him is forbidden.) And the first tanna holds that since in the beginning he did not intend to worship it, his subsequent worship of it, since it is attached to the ground, does not forbid it, it being comparable to worshiping a mountain. The halachah is not in accordance with R. Yossi.] R. Akiva said: I will explain and analyze for you: Wherever you find a high mountain and a high hill and a leafy tree, know that there is idolatry there. [i.e., since we cannot expound the exclusion clause of "under every leafy tree," we can say that it was stated only to give them signs of where the Emorites were likely to serve idolatry, so that Israel should seek it out and destroy it. And "upon the mountains" and "upon the hills" (Ibid. 12:2) are understood as exclusion clauses, that we are not commanded to destroy the mountains themselves (but what is upon them). But we are commanded to destroy the leafy trees, viz. (Ibid. 3): "And their asheiroth shall you burn in fire."]