Matthew Poole and continuators on Zechariah 2:8

8 For thus saith the LORD of hosts, After the glory hath he sent me to the nations which spoiled you: for he that toucheth you, toucheth the apple of his eye.

Some refer this to what went before, as a reason why the Jewes should return, for God hath commanded it. I think 'tis an encouragement to the Jewes to return, because God had promised to make them a glory, and now assures them that he will take a very particular care of them, therefore sends his Son, as a Judge, or Vindex, against the Nations that had spoiled the Jewes, or God sends his Son to them to inform them that 'tis their interest to unite with the Jewes, and become the people of God, and be partakers of the Glory, and safety of Gods Israel. However to let them understand that 'twill be dangerous to do violence to Israel, as it would be dangerous to any one to violate what is most dear to him that can destroy the offender; to tell them Israel is the Apple of Gods Eye.

Marginal references: Deut. 32.10. Psal. 17.8.