She smote off his head - The original does not warrant this translation; nor is it supported by fact. She smote his head, and transfixed him through the temples. It was his head that received the death wound, and the place where this wound was inflicted was the temples. The manner in which Jael despatched Sisera seems to have been this:
2. She then took a tent nail and drove it through his temples, and thus pinned him to the earth; which she could not have done had she not previously stunned him with the blow on the head. Thus she first smote his head, and secondly pierced his temples.
Rather “she smote his head, and she struck and pierced through his temple.”