A Very Strange Proverb

I was reading in Proverbs 22 for my devotional, and came across something so strange I had to post about it. It's verse 14, which in the ESV reads, "The mouth of forbidden women is a deep pit; he with whom the LORD is angry will fall into it."

That's odd, I thought. Don't you? Isn't that incorrect grammar? "Mouth" doesn't match in number with "forbidden women." I thought I'd try the old King James to see what it said. That same verse reads, "The mouth of strange women is a deep pit: he that is abhorred of the LORD shall fall therein." There it is again, this mismatch of number. So now I was curious. Did every version translate it this way? The NIV does not. It reads, "The mouth of an adulteress is a deep pit; he who is under the LORD's wrath will fall into it." The NASB also matches number, as does the NKJ. The old American Standard Version does not match number. So out of six translations that a conservative Presbyterian like me could trust, fully three of them have a mismatch in number, including my favorite translation, the ESV. Perhaps Lane could enlighten me as to what the Hebrew says; surely number is easily verified in the original.

What is the reason? If the best translation is a mismatch in number, what could this proverb be saying? Well, one possible explanation is that perhaps the identification of "mouth" with "forbidden women" emphasizes the "deep pit"-ness of them all. A mouth is a pit of sorts (for those teenagers out there that would be 'bottomless pits'). So the warning is against the mouth, which we know from other Proverbs will drip honey but conceal death. I'd be interested in your thoughts.

In Christ.