http://revach.net/article.php?id=5144

Section: Parshas HaShavua   Category: Quick Vort
Parshas Ki Seitzei: Rav Moshe Feinstein - Even Moavi Prostitutes Can Be Shy

The Torah forbids us to accept into Klal Yisrael Moavim (Ki Seitzei 23:4), because they didn't greet us with bread and water when we left Mitzrayim. The Gemara (Yevamos 76b) says that Moavi women may be Migayer since it is not proper for women to leave their homes to greet passersby, even to greet the females of Klal Yisrael . This was the reason why Dovid who came from Rus was Kasher.

Rav Moshe Feinstein says that this is mind boggling. In the episode of Bilam the Moavi women were more than eager to seduce the men of Bnei Yisrael. Where was their Tzniyus then?

Rav Moshe answers that it is entirely possible that by nature they were indeed very modest. It was the persuasion of the Yetzer Hara that they could not resist in the call to fight Klal Yisrael. Hashem knew their real nature and therefore did not hold them accountable for not being hospitable to Klal Yisrael. Furthermore, he knew that if they chose to become part of Klal Yisrael this Middah would serve them well. Therefore Moavi women, unlike the men, are able to be Migayer and become model Jews.