יורה דעה ק״מYoreh De'ah 140

Se’if 1א׳

עֲבוֹדַת כּוֹכָבִים וּמְשַׁמְּשֶׁיהָ וְתִקְרָבְתָּהּ, אוֹסְרִים בְּכָל שֶׁהוּא, שֶׁאִם נִתְעָרֵב אֶחָד מֵהֶם, אֲפִלּוּ בְּאֶלֶף, כֻּלָּן אֲסוּרוֹת. וְאִם אֶחָד מֵהַתַּעֲרֹבֶת הָרִאשׁוֹן נִתְעָרֵב בִּשְׁנַיִם אֲחֵרִים, וְנָפַל מֵהַשְּׁלשָׁה אֶחָד לִשְׁנַיִם אֲחֵרִים, הֲרֵי אֵלּוּ הָאֲחֵרִים מֻתָּרִים. וְכֵן אִם אֶחָד מֵהַתַּעֲרֹבֶת הָרִאשׁוֹן נָפַל לַיָּם אוֹ נִשְׂרַף בְּעִנְיָן שֶׁנֶּאֱבַד מֵהָעוֹלָם, כָּל הַנִּשְׁאָרִים מֻתָּר לֵהָנוֹת בָּהֶם שְׁנַיִם שְׁנַיִם בְּיַחַד, אֲבָל לֹא הָאֶחָד לְבַדּוֹ. וּבִלְבַד שֶׁלֹּא יֵהָנֶה אָדָם אֶחָד מִכֻּלָּם. וְיֵשׁ מִי שֶׁאוֹסֵר אֶלָּא אִם כֵּן נָפְלוּ שְׁתַּיִם לַיָּם הַגָּדוֹל אוֹ נִשְׂרָפִים וְעַיֵּן לְעֵיל סִימָן ק"י.

An idol, and its appurtenances, and its offering, render forbidden in any amount at all; for if one of them became mixed even in a thousand, all of them are forbidden. And if one of the first mixture became mixed with two others, and from the three one fell into two others, these others are permitted. And likewise, if one of the first mixture fell into the sea or was burned in such a manner that it was lost from the world, all that remain — it is permitted to derive benefit from them two by two together, but not from one alone; provided that one man does not derive benefit from all of them. And there is one who forbids unless two fell into the Great Sea or were burned. And see above, siman 110.