Commentary for Isaiah 21:15

Since because of the swords they wandered (I.e.,) my people (wandered).

For they fled from the swords. They, that are wandering about, are fleeing because of the king of Assyria.

the outstretched sword (נְטוּשָׁה), spread over the surface of the earth, as (I Sam. 30:16) “And behold, they were scattered (נְטוּשִׁים) over the entire landscape,” (II Sam. 5: 18) “And spread out (וַיִּנָּטְשׁוּ) in the Valley of Rephaim.” Another explanation is that נְטוּשָׁה is like לְטוּשָׁה, sharp. All letters whose sources are close to being from one place, (i.e., from one speech organ,) are interchangeable with one another, the ‘nun’ with the ‘lamed,’ as in the case stated (in Nehemiah 13: 7): “To make him a chamber (נִשְׁכָּה),” like לִשְׁכָּה.