Zion is astonished by the sudden, massive return of her exiled children. God responds to this wonder by acting as a king or military commander signaling His troops. He declares that He will alert the nations of the world that the time of redemption has arrived, and these very nations will be the ones to escort the Israelites back to their homeland with profound respect and gifts.
The primary approach among commentators is that God will provide a divine sign, waking the nations to gather the exiles and bring them to safety [רש״י, אבן עזרא, מצודת דוד, שד״ל, שטיינזלץ]. This signal is compared to a tall pole flying a flag, serving as a highly visible gathering point for the masses [רש״י, מצודת ציון]. While some view the dual imagery of God lifting His hand and raising a banner as simple emphasis [מצודת דוד], others see a distinction based on the status of the various nations. Lesser nations will require only a subtle hint, like the raising of a hand, to release the exiles. In contrast, greater nations will demand a much stronger sign, such as a banner hoisted during a massive war, before they finally submit and return the Israelites [מלבי״ם]. Another unique perspective suggests that the raised hand represents heavenly plagues destined to strike the nations in the end of days. These plagues will miraculously bypass hidden Jews who had assimilated, thereby exposing their true identity and prompting the nations to bring them forward as a tribute [אהבת יהונתן].
When the nations bring the Israelites back, they will do so with deep affection and honor. The returning exiles are described as being carried closely and protectively, much like a person cradling a precious object in the fold of their garment [רש״י, מצודת ציון, אבן עזרא, שד״ל, שטיינזלץ, צאינה וראינה]. Alternatively, this protective embrace is understood simply as being held safely in the arms [רד״ק], or even being carried in special chairs of honor reserved for dignitaries [מלבי״ם].
The picture of the return is made complete by the image of daughters being carried on shoulders, evoking the gentle way young children are carried for their own enjoyment [מצודת ציון, שטיינזלץ, צאינה וראינה]. Some explain the different methods of transport by noting that the daughters might be afraid to sit in the towering chairs of honor provided for the sons, making the shoulder a safer, more comforting place for them [מלבי״ם]. Another view suggests that being carried on the shoulder points to the very young age of these returning girls. According to this thought, only the youngest girls, who had not yet fully assimilated into foreign cultures, will be permitted to marry priests once they return to the holy land of Israel [אהבת יהונתן].