Zechariah 2:9
For, behold, I will shake mine hand upon them, and they shall be a spoil to their servants: and ye shall know that the LORD of hosts hath sent me. For, behold, I will shake mine hand upon them, and they shall be a spoil to their servants: and ye shall know that the LORD of hosts hath sent me.
The verse belongs to Zechariah's encouraging visions given when the returned exiles feared that permission to rebuild Jerusalem and the temple would be withdrawn. It accompanied God's call for the scattered Jews, especially those still in Babylon, to leave exile and return to Jerusalem before trouble came under Xerxes' reign. God declares He will shake His hand upon the nations that plundered and afflicted His people, making those oppressors become spoil to their own servants, the people they had oppressed. That reversal will make known that the Lord of hosts sent the messenger delivering it.
The promised intervention is part of God's work through Messiah to relieve His afflicted people. The Lord comes to that relief in pity toward His afflicted people and in answer to intercession, as His answer to their affliction. Satan opposes that work by standing before the angel of God to resist the Lord's working for His people and to resist every church and ministers of the gospel in their official work of ministering the Word.
In its wider promise the verse shows God's protection of His church, which He guards through trials and purifies without allowing it to be consumed. In view of that work the church and its leaders are called to repentance and obedience.