Your unworthy younger brother Wei Zheng, bowing his head, respectfully addresses this letter to his sworn elder brother, the Grand Registrar, venerable Master Cui:

The salutation, and it is doing more work than it looks. 辱愛弟 is a set humbling formula — roughly "your unworthy younger brother, whom you condescend to be fond of." 頓首, "knocking the head," is the written equivalent of a deep bow, the way a Western letter might once have closed "your obedient servant." 大都案 is the Grand Registrar's office, the same post as 掌案判官; 都 here is dū. 契兄 is a sworn elder brother, not a blood one, and 臺下 is a respectful way of addressing him. Wei Zheng is writing to hell as an old friend, and pulling rank on the friendship.

I recall our old companionship — your voice and face seem present still. Yet in the space of a few swift years I have heard nothing of your pure counsel.

音容如在, "voice and face as though still here," is the standard phrase for remembering the dead. 倏爾 is "in a flash." 數載, shù zǎi, is "a few years" — 載 read zǎi in its "year" sense, not zài, "to carry." 清教, "your pure instruction," is a polite way of saying "anything you had to say."

At each turning of the seasons I have only set out plain offerings in sacrifice, though I cannot tell whether you have received them.

The apologetic middle of any letter to the dead: I have been keeping up the offerings, I hope. 節令 are the seasonal festivals when families sacrifice. 蔬品 are plain meatless offerings. 未卜 — 卜 is bǔ, to divine — means "I cannot know," and 享 here is the technical verb for a spirit accepting what is offered.

Then, of your kindness, you did not forsake me but appeared before me in a dream, and so I first learned that my elder brother had risen to high estate.

Then the news, and the flattery. 承不棄 is "you deigned not to drop me." 臨示 is to appear and show oneself, here in a dream — the only postal service available in this direction. 高遷 is a promotion, and Wei Zheng is congratulating his friend on a career move into hell.

But alas, the quick and the dead are sundered, each in a separate quarter of the world, and we cannot meet face to face.

The obligatory line of regret before the ask. 陰陽兩隔 is "the shadow world and the sunlit world, kept apart"; 天各一方, "each under a different corner of the sky," is still a live expression for people separated by distance. 面覿, miàn dí, is to see face to face.

Now, because my sovereign, the Cultured Emperor Taizong, has suddenly passed away and must, I reckon, face the three tribunals, he will surely come to meet with my elder brother.

Now the reason for writing. 文皇帝, "the Cultured Emperor," is one of Taizong's formal titles. 倏然而故 is "died suddenly." 對案三曹 is the same three-party hearing as 三曹對案, with the words swapped for the rhythm. 相, xiāng, in 相會 is "with each other."

I entreat you ten-thousand-fold: bending your thoughts upon the friendship of our living days, grant a small favour or two, and release my sovereign to return to the light — it would be a singular kindness.

And here is the request, phrased as if it were a small thing. 萬祈 is "I beg you ten thousand times." 俯念 is to bend your mind down to something. 生日交情 means the friendship of our living days — 生日 is 生時 here, not "birthday." 方便一二 is "extend a convenience or two," the language of asking a colleague to bend a rule; 一 is read yī as a counted numeral. 回陽 is to go back to the world of the living. 為 here is wéi, "to be." A favour or two, if you would — namely, resurrect the emperor.

I shall render fuller thanks another time. Words cannot exhaust it.

The sign-off. 容再修謝, "allow me to thank you more fully another time," is boilerplate. So is 不盡, "I cannot say it all" — the Chinese equivalent of "yours ever." 盡 is jìn, and 不 before it accordingly rises to bú.