Jerusalem would experience captivity as Sodom and Samaria had. Evidently the Lord meant that the people of Sodom had experienced captivity in the sense that He had taken them away. Jerusalem"s captivity would bring humiliation and shame to her people when they realized that their judgment had been a comfort to the people of Sodom and Samaria. Obviously these people were now dead, but the parabolic form of this message allows for some unusual details. Jerusalem"s captivity had showed them that Jerusalem was worse than these towns. Yet the Lord would end the captivity of all these towns; their descendants would have a future (cf. Deuteronomy 30:3). [source][source][source]
"The main point seems to be that God"s willingness to restore Jerusalem, despite the magnitude of her sin, offers hope for other sinful nations, even those who violate his moral standards in blatant ways." [1][source]