ἐν πέτροισι πέτρον ἐκτρίβων → by grinding stone against stones
dē-mŭtĭlo: āre,I v. a., to lop off: cacumina virgarum, Col. Arb. 11, 2.
dēmŭtĭlō, āre, tr., retrancher, élaguer : Col. Arb. 11, 2.
