The release of the Israelites from exile and the enemies who rule over them is rooted in a deep relationship of closeness and salvation with God. The primary approach among commentators is that God employs two distinct forms of rescue to free the nation from its captors. The first form is an act of mercy, similar to paying a ransom to release a prisoner. The second form of rescue is driven by an intense personal closeness, resembling a loyal relative who is ready to fight and risk everything to save their family [מלבי״ם]. God actively uses both of these methods to deliver the Israelites.
This divine intervention is necessary because the enemies holding the Israelites captive possess far greater strength than the exiles themselves [מצודת דוד, מלבי״ם, ביאור שטיינזלץ]. However, an alternative approach suggests a different dynamic, where the rescue will actually be brought about by the enemy itself. In this view, the captors will step forward to testify that the Israelites faithfully observed the Torah, and this very testimony will lead to their freedom [חומת אנך].
Following this complete rescue, the liberated nation will return to Zion to sing praises to God. They will be blessed with tremendous physical abundance, enjoying plentiful grain, wine, oil, and flocks. Their society will thrive and grow like a lush, well-watered garden, marking the absolute end of their period of sadness and mourning [צאינה וראינה].