The names of these cities here refer to the people who live in them. Alternate translation: "say to the people of Jerusalem ... people of Zion" (See: [[rc://en/ta/man/translate/figs-metonymy]])
To feel weak or helpless is spoken of as if their hands became physically weak. Here "hands" represents the whole person. Alternate translation: "Do not become weak" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-synecdoche]])