She put her hand to the nail
Her left hand, as the Septuagint, Arabic, and Vulgate Latin versions express it, and as appears by what follows; she having taken up a pin from her tent, with which it was fastened to the ground, she clapped it to the temples of Sisera:
and her right hand to the workman's hammer;
in her right hand she took a hammer, such as carpenters, and such like workmen, make use of, and workman like went about her business she had devised, and was determined upon, being under a divine impulse, and so had no fear or dread upon her:
and with the hammer she smote Sisera;
not that with the hammer she struck him on the head, and stunned him, but smote the nail she had put to his temples and drove it into them:
she smote off his head;
after she had driven the nail through his temples, she took his sword perhaps and cut off his head, as David cut off Goliath's, after he had slung a stone into his forehead; though as this seems needless, nor is there any hint of it in the history of this affair, the meaning may only be, that she struck the nail through his head, as the Septuagint, or broke his head, as the Targum:
when she had pierced and stricken through his temples;
that being the softest and tenderest part of the head, she drove the nail quite through them to the ground, ( Judges 4:21 ) .
The Brenton translation of the Septuagint is in the public domain.