What does "shall be" mean?
Native speaker’s answer
Rebecca
"Shall" is a verb that expresses strong future intent and is similar but stronger than "should", "will", and "must". "Shall" is only used to emphasize these words very strongly, and so it is often used as a command. In this context, "shall be" means that it "will be" in the future. Here this refers to the fact that the baby Jesus in the manger will be a sign to them. Ex: You shall be a great leader one day.