"If one strikes a man": This (i.e., both verses) tells me only of a man or a woman who kills a man or of a man who kills a woman or a minor. Whence do I derive (the same for) a woman who kills a minor or (another) woman? It is, therefore, written (Numbers 35:16-17) "The murderer shall be put to death … he is a murderer." It comes for this teaching (i.e., that a woman, too, is liable for killing a woman or a minor).