AMO 1:6

6 Yahweh [also] said this [to me]: “[I will punish the people of the cities in Philistia]: [I will punish the people of] Gaza [city] because of the many sins that they have committed; I will not change my mind about punishing them, because they captured large groups of people and took them to Edom and sold them to become the slaves of [the people of] Edom.