What are the two details described in the poem in {{Meeting the Beijing Messenger}}? Please tell me how these two details express the poet's feelings respectively.

"There is no pen and paper when we meet, and there is news from you when we report peace." These two sentences are about the situation that you met an emissary in Beijing and wanted to take a book home to report peace, but there was no pen and paper. They were completely anxious to see the traveler at once, and they behaved very vividly. The word "meet" points out the topic. On the way to Anxi, I met an old friend, who was the messenger to Beijing. They all rode on horseback, arms crossed. One went west, and the other returned to Chang 'an in the East. His wife was in Chang 'an, and she just asked her old friend to bring back a letter of peace, but she had no pen and paper and no time to write, so she had to ask her old friend to take a message. This last poem is very concise and neat, but it contains the poet's deep affection, faint taste and charm in simplicity. Cen Can came here with the ambition of "fame and fortune". At this time, the mood is complicated. On the one hand, he has tenderness and homesickness for the imperial city, on the other hand, he also shows the poet's open and heroic mind.