TT #314 · Parashas Shoftim · Seventh Aliyah · Passuk 20:11
And it shall be, if it answers you with peace and opens to you, then all the people found in it shall be tributary to you and shall serve you.
Torah Temimah points to Sifrei Devarim 200.
TT lemma: יִהְיוּ לְךָ לָמַס וַעֲבָדוּךָ.
English: ‘They shall be tributary to you and shall serve you’ – tributary service.
Derash defining the tribute (Sifrei) — the peace terms include service and taxation.
The peaceful settlement places the city’s population under tribute and service to Yisrael.