דֶּ֣רֶךְ רְ֭שָׁעִים כָּֽאֲפֵלָ֑ה לֹ֥א יָ֝דְע֗וּ בַּמֶּ֥ה יִכָּשֵֽׁלוּ׃ (פ)
The way of the wicked is as darkness; They know not at what they stumble.
Rashi on Proverbs
The way of the wicked is like pitch darkness; they do not know on what they stumble Suddenly, an obstacle will come to them, and they will not know how to beware of it.