Tell me the answer to this poem.

1. The poet heard the news of recovering northern Hebei outside the sword gate, and his clothes were wet with tears of joy. Expressed his patriotism.

Don't forget to tell your father the good news when you hold a family sacrifice when the Song army recovers the lost land in the Central Plains.

Reached the poet's deep and strong patriotic feelings of "northern expedition to the Central Plains" and reunification of the motherland until his death.