Deuteronomy 20:11 in the King James Version
And it shall be, if it make thee answer of peace, and open unto thee, then it shall be, that all the people that is found therein shall be tributaries unto thee, and they shall serve thee.
Context
10 When you draw near to a city to fight against it, then proclaim peace to it.
11 It shall be, if it gives you answer of peace and opens to you, then it shall be that all the people who are found therein shall become forced laborers to you, and shall serve you.
12 If it will make no peace with you, but will make war against you, then you shall besiege it.