Because of their family mission, one of them had to guard the bronze gate, and the other had to look for Mulan grass. One is immortal and never grows old, the other is cursed until his death. It is also an extravagant hope for them to have white heads in the world. Only when the snow from Changbai Mountain accidentally falls on their hair can they be considered to have white heads together in the world.
Intention: love and persistence