The apple of an eye refers to the pupil of the eye, which is one of the most sensitive parts of the body. The idiom "apple of the eye" refers to something that is most valuable. Here it means that God greatly values Jerusalem. AT: "what is most valuable to God" (See: [[rc://en/ta/man/translate/figs-idiom]])
Raising one's hand against another person is a gesture of hostility. Here it is a symbolic action that means that God will attack those who harm Jerusalem. AT: "I myself will fight against them" or "I myself will attack them" (See: [[rc://en/ta/man/translate/translate-symaction]])