Deuteronomy 32:5

שחת לו — Take it as the Targum has it: חבילו להון לא לה “Corruption is theirs, not His”. בניו מומם HIS CHILDREN, THEIR FAULT — i.e., they were His children, and the corruption which they wrought is their fault. בניו מומם means: it was the fault of His children not His fault. דור עקש means, [A] CROOKED AND PERVERTED [GENERATION]. עקש has the same meaning as the verb in (Micah 3:9) “and pervert (יעקשו) all equity”. In Mishnaic Hebrew we have (Chullin 56a): a weasel whose teeth are bent and crooked (עקושות). ופתלתל entortille in old French, Engl, twisted: like a thread (פתיל), which one twines and twists round the central strand. The word פתלתל is of the “doubled” words (in which the two last letters are the same), like (Leviticus 13:49): ירקרק. אדמדם; (Psalms 38:31): סחרחר; (‎1 Kings 7:23; Targum Jonathan on): סגלגל‎.

Not his the corruption, but the blemish of his sons: they are a perverse and crooked generation.

שִׁחֵ֥ת ל֛וֹ לֹ֖א בָּנָ֣יו מוּמָ֑ם        דּ֥וֹר עִקֵּ֖שׁ וּפְתַלְתֹּֽל׃