Midrash for Berakhot 8:6
אֵין מְבָרְכִין לֹא עַל הַנֵּר וְלֹא עַל הַבְּשָׂמִים שֶׁל עוֹבְדֵי כוֹכָבִים, וְלֹא עַל הַנֵּר וְלֹא עַל הַבְּשָׂמִים שֶׁל מֵתִים, וְלֹא עַל הַנֵּר וְלֹא עַל הַבְּשָׂמִים שֶׁלִּפְנֵי עֲבוֹדָה זָרָה. אֵין מְבָרְכִין עַל הַנֵּר עַד שֶׁיֵּאוֹתוּ לְאוֹרוֹ:
One does not make the blessing over the candle or the spices of idolators [Not over the candle, because it did not "rest," the idolator having worked by its light; and it is forbidden to make a blessing over a candle that did not rest, a transgression having been committed by it. And not over the spices of idolators. The reference is to spices used in a festive gathering of idolators. And this is the intent of the latter part of the Mishnah: "And not over the candle and not over the spices before idolatry," i.e., Why does one not make a blessing over the spices of idolators? For it may be assumed that a festive gathering of idolators is for idolatrous proposes and it is forbidden to make a blessing on spices used for idolatry.] and not over the candle and the spices used for the dead, [the candle (for the dead) being used for honorific purposes, and the spices being used to dispel odor.] And not over the candle and not over the spices before idolatry. One does not bless over the candle until he benefits by it [by its light. Not that he benefit by it, per se, but that he be close enough to benefit by it if he wishes to.]