Blessingsare on the head of the righteous,
but the mouth of the wicked concealsviolence.
As with the last few chiasms in Proverbs that I've written about, the elements here are a bit more loosely equated, but the structure does highlight the contrasts between "blessings" and "violence" and between "the head of the righteous" and "the mouth of the wicked."
This chiasm is also in the Hebrew:
בְּרָכוֹתלְרֹאשׁ צַדִּיק
וּפִי רְשָׁעִים יְכַסֶּהחָמָֽס׃
and the Latin Vulgate:
benedictiosuper caput iusti
os autem impiorum operitiniquitatem
It's also in my German translation of Proverbs, but the meaning is a bit different:
Segen ruhtauf dem Haupt des Gerechten;
aber auf die Gottlosenwird ihr Frevel fallen.
Something like:
Blessing restson the head of the righteous,
but on the wickedwill their iniquity fall.
The second half of this echoes Psalm 7:16: "His mischief returns upon his own head, and on his own skull his violence descends."