Deuteronomy 32:17

לא אלה — Understand this as the Targum does: They sacrifice unto devils in which is no utility, for if there were at least any utility in them to the world (as e.g:, the sun, moon and stars) God’s jealousy would not have been so intense (lit. — doubled) as it is now. (Sifrei Devarim 318:13). חדשים מקרב באו [THEY SACRIFICED … TO GODS] THAT CAME UP RECENTLY — i.e. with which even the heathen nations were not familiar. Indeed, if a heathen saw them he would say, “This is a Jewish idol” (Sifrei Devarim 318:14). לא שערום אבתיכם — This means, which your fathers feared not; more literally it means: Their hair (שער) did not stand up on end because of them — for it is the nature of a person’s hair to stand up out of fear. Thus is it (the word שערום) explained in Sifrei Devarim 318:15. But it is also possible to explain it as being connected with the noun in (Isaiah 13:21) “And שעירים shall dance there”; שעירים are demons (satyrs), and the meaning of our verse would then be: your fathers never made these satyrs.

They sacrificed to powerless spirits; to gods whom they knew not, to new gods that came newly up, whom your fathers feared not.

יִזְבְּח֗וּ לַשֵּׁדִים֙ לֹ֣א אֱלֹ֔הַּ אֱלֹהִ֖ים לֹ֣א יְדָע֑וּם        חֲדָשִׁים֙ מִקָּרֹ֣ב בָּ֔אוּ לֹ֥א שְׂעָר֖וּם אֲבֹתֵיכֶֽם׃