Commentary for Isaiah 13:15

Everyone who is found outside, shall be stabbed.

He will be pierced. He will find no mercy.

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.

נספה That is joined. Participle Niphal.¹⁸The participle Niphal is called by I. E. adjective (שם התואר). Comp. Zahoth, On the Niphal.