ציטירנדיקער פּירוש אויף צפניה 3:18

from those who pass by confidently, who return from war—Instead of passing by confidently, as they expected to, they became like men returning from war without clothing or food, for their enemies took everything they had. who return Heb. שׁוּבִי, as in (Jer. 2:21) “A degenerate (סוּרֵי) wild vine” and (Zeph. 3:18) “Those taken away (נוּגֵי) from the appointed season.”

לנוס (the passive participle) has the same meaning as לַנָּס (the active participle), just as, (Micha 2:8) "שובי מלחמה”, which means “those who have returned from battle”; and so, too, (Zephaniah 3:18) “those who are removed far (נוני) from the appointed season”; (Joshua 5:5): “for they were circumcised men (מולים)”. Now just as you say שוב in reference to one who has already returned, and מול in reference to one who is already circumcised, so you can say לנוס in reference to one who has already fled. It calls him נוס (the passive participle), as much as to say “one who was made to flee”; — But you say that לנוס means “to flee” (the infinitive) explaining it thus: “ye shall take no ransom for one who ought to flee”, in order to free him from exile (cf. Sifrei Bamidbar 160:12), then I do not know how it can be said: “ye shall take no ransom … so that he should return to dwell in the land”, for you see, he has not yet fled, so from where shall he return?