If I ignore the memory of you, Jerusalem

The writer speaks as if Jerusalem is listening to him. Alternate translation: "If I act as if I did not remember you, Jerusalem" or "If I try to forget you, Jerusalem" (See: rc://en/ta/man/jit/figs-personification and rc://en/ta/man/jit/figs-apostrophe)

right hand

the hand most people use most often