BT Šab 95a(19) :קטיל קני באגמי הוה‏ : your teacher was one who used to cut down reeds in the marshes [i.e. was not versed in the Oral Law]
See the entire entry for qṭl vb. to kill

BT Šab 95a(19) :רבך קטיל קני באגמי הוה‏ : your teacher was one who used to cut down reeds in the marshes [i.e. was not versed in the Oral Law; v. supra]
See the entire entry for qnē, qanyā n.m./f. reed