BT Ket 77b(22) :ושאדי אר̇{{ו}}^י^̇שיה עד דרפייא ארעיתא דמוחיה וקרע ל^י^ה למוחיה‏ : he pours (three hundred bowlfuls of water) on his head until the bottom of his skull becomes soft, and he cuts open his skull
See the entire entry for mūḥ, mūḥā n.m. brain