Charles Ellicott Commentary Psalms 140:9

"As for the head of those that compass me about, Let the mischief of their own lips cover them." — Psalms 140:9 (ASV)

Head.— Ewald, who keeps to the text, takes rôsh in the sense of poison (see Psalms 69:22, Note):

“The poison of those encircling me,
Let them be covered with the perdition of their lips.”

This brings Psalms 140:8-9 into harmony with Psalms 140:4. But the emendation given above is better.