Zechariah 10:8

I will hiss for them "Formerly God had so spoken of His summoning the enemies of His people to chastise them (Isaiah 7:18-19; Isaiah 5:26-27). He would gather them like the countless numbers of the insect creation, which if united would irresistibly desolate life. He would summon them as the bee-owner, by his shrill call, summons and unites his own swarm. Now, contrariwise, God would summon with the same His own people. The fulfilment of the chastisement was the earnest of the ease of the fulfilment of the mercy." Pusey.

as they have increased i.e. formerly in Egypt. Exodus 1:7; Exodus 1:12. "Multiplicabuntur in exsilio, ut multiplicati fuerunt in Ægypto." Jarchi, quoted by Maurer. Comp. Ezekiel 36:10-11.