נחמיה, פרק י״ג, פסוק ג׳

Hearing the laws of the Torah read aloud inspired the Israelites to take immediate action to protect their identity. Recognizing the danger of assimilation, the people separated from foreign elements living among them to maintain the purity of their national lineage.

The commentators agree that this separation involved a mixture of non-Israelites residing within the community. Some scholars view this group broadly as general idolaters and foreigners, echoing the mixed multitude that joined the Israelites when they left Egypt [רש"י, רס"ג]. In contrast, the majority of commentators identify this specific group as Ammonites and Moabites who had integrated into the nation [רלב"ג, מצודת דוד, שטיינזלץ, מלבי"ם]. This included converts from Ammon and Moab, and the swift decision to distance them was rooted in the strict religious prohibition against intermarrying with these specific nations [רלב"ג, מלבי"ם].

This historical event presents a practical question. Following the widespread conquests and exiles carried out by Nebuchadnezzar, entire populations were relocated and mixed together, causing many nations to lose their original, distinct identities. Given this massive displacement, it seems difficult to understand how the Israelites could identify individuals as definitively Ammonite or Moabite. However, during this era, which was still relatively close to the destruction of the Temple, the mixing of populations was not yet absolute. There were still individuals from Ammon and Moab whose national origins remained clear and well-known, allowing the community to accurately identify and separate from them before they were completely absorbed into the general population [מלבי"ם].