כָּל־הַנִּמְצָ֖א יִדָּקֵ֑ר וְכָל־הַנִּסְפֶּ֖ה יִפּ֥וֹל בֶּחָֽרֶב׃
凡被找到的人都必被刺殺；凡依附加入他們的人都必倒在刀下。
Rashi
and anyone who takes refuge with the people of the city to be included with them in the siege, shall fall by the sword when the city capitulates. נִסְפֶּה is an expression similar to (Deut. 29:18): “To add the unintentional sins to the lustful ones (סְפוֹת)”; (infra 29:1) “Add year upon year (סְפוּ)”; (Jer. 7:21) “Add (סְפוּ) to your sacrifices.” [akojjlir in O.F.], to join.