Deuteronomy 20:10-11

20:10 When you approach a city to wage war against it, offer it terms of peace. 20:11 If it accepts your terms ¹  and submits to you, all the people found in it will become your slaves. ² 

[20:11]  ¹ tn Heb “if it answers you peace.”

[20:11]  ² tn Heb “become as a vassal and will serve you.” The Hebrew term translated slaves (מַס, mas) refers either to Israelites who were pressed into civil service, especially under Solomon (1 Kgs 5:27; 9:15, 21; 12:18), or (as here) to foreigners forced as prisoners of war to become slaves to Israel. The Gibeonites exemplify this type of servitude (Josh 9:3-27; cf. Josh 16:10; 17:13; Judg 1:28, 30-35; Isa 31:8; Lam 1:1).