Rashi on Ki Sisa 33:3

English: ארץ זבת חלב ודבש UNTO A LAND FLOWING WITH MILK AND HONEY do I bid you to bring them up. כי לא אעלה בקרבך BECAUSE I WILL NOT GO UP AMONG THEE, therefore I say to thee, I will send an angel before thee. כי עם קשה ערף אתה FOR THOU ART A STIFF-NECKED PEOPLE, and if My Shechina were in thy midst and thou rebelledst against Me, I might become exceedingly angry with thee and destroy thee on the way. אכלך is an expression for ‘‘destroying”.