I was somewhat surprised the first time I heard this passage cited as a proof that a woman should not use a groin strike against a male in self-defense. Then I realized that before I discount that application, I should examine the passage more closely. Let's begin with context.
These verses appear at the end of a discussion of levirate marriage (Deut. 25:5-10). That is, when a man of Israel died childless, his nearest male blood relative was to take the widow as wife in order to produce offspring. The firstborn of that union would be counted as the dead man's descendant and heir. This demonstrated the importance of heritage in the covenantal Law of God & is key to understanding the next two verses. (For an insightful discussion of this passage, see Gary North's "Levirate Marriage and Family Name" in his commentary on Deuteronomy, Inheritance and Dominion.)
Commentators who do not see the point of verses 5-10 often miss the point of verses 11-12. Take Keil & Delitzsch, for example:
“But in order that the great independence which is here accorded to a childless widow in relation to her brother-in-law, might not be interpreted as a false freedom granted to the female sex” (Baumgarten), the law is added immediately afterwards, that a woman whose husband was quarrelling with another, and who should come to his assistance by laying hold of the secret parts of the man who was striking her husband, should have her hand cut off.
The point of this ordinance is not to quell licentious sexuality, nor is it to punish immodesty (as in Matthew Henry & John Gill's comments). To grab a man by the stones is to take his covenantal continuity and heritage in your hands. It goes against the whole tenor of God's declarations regarding children and the future (Psa. 127:3; Mal. 2:15). Now, with an understanding of the passage's theme and purpose, let's proceed to analyze what it says.
"When men strive together . . . ."
The word translated strive means to struggle (Brown-Driver-Briggs), although it is used here to denote a physical fight (as also Exodus 2:13 & 21:22), it also may express a verbal altercation or quarrel (as in Num. 26:9). Gill paraphrases "strive together" as, "Quarrel with one another, and come to blows, and strive for mastery, which shall beat, and be the best man". Thus the language here indicates a fight rather than a criminal assault.
Men (primarily) enter into fights by mutual consent. If you've ever watched a quarrel escalate into a fight, you recognize that, in most cases, either of the men could have headed off the violence by simply leaving the scene. Instead, neither would give in until the argument became so heated that one of them touched (poked, prodded, pushed) the other. Then the other responded physically. Usually a shoving match precedes the actual throwing of punches.
What we see in this passage is not a man jumped by an assailant in an alley. We see a man who has abdicated control of his anger and entered into an ill-advised hostile encounter with another man (presumably another Israelite, a fellow-believer - reminds me of some church business meetings [oops, off topic]). And he's losing.
Then his wife takes matters in hand.
". . . and taketh him by the secrets."
Although he does not fully grasp the covenantal import, Gill recognizes the motives and possible consequences of such an act:
This immodest action was done partly out of affection to her husband, to oblige his antagonist to let go his hold of him; and partly out of malice and revenge to him, to spoil him, and make him unfit for generation, and therefore was to be severely punished . . . .
When God made the promise of the seed to Abraham (Gen. 17:7), no one knew precisely who that seed would be or how He would come. We see the Messianic prophecies much more clearly in retrospect than did the average Israelite under the Mosaic covenant (Gal. 3:17ff). Therefore to interfere with another Israelite's potential seed was an affront to God's covenant with His people, and an attack on His plan of redemption. It was, in fact, so heinous an act, that it demanded a punishment quite extraordinary by Biblical standards.
Thus, Albert Barnes observes:
This is the only mutilation prescribed by the Law of Moses, unless we except the retaliation prescribed as a punishment for the infliction on another of bodily injuries Lev 24:19-20.
Summary & Conclusion
This ordinance is about the fact that when a man gets involved in a foolish quarrel, even his own safety and well-being do not take precedence over the purposes and promises of God. His wife may not rescue him from the consequences of his prideful and willful pugnacity by violating another believer's covenantal continuity and heritage.
The context, theme and purpose of this law have nothing to do with a circumstance in which a mugger or rapist grabs a woman on the street. In my experience, women are hesitant enough (because of modesty and natural aversion to violence) to consider defending themselves by grabbing a man's stones. We don't need to add the hindrance of misplaced guilt resulting from incomplete exegesis to a woman's hesitancy.
I would counsel my wife and daughters that, in the event of attempted assault: "If the groin shot presents itself, consider it God's providence & take it."
