Grammar

 蘇秦之楚，三日乃得見乎王。談卒，辭而行，楚王曰：“寡人聞先生，若聞古人。今先生乃不遠千里而臨寡人，曾不肯留，願聞其說！”對曰：“楚國之食貴於玉，薪貴於桂，謁者難得見如鬼，王難得見如天帝。今令臣食玉，炊桂，因鬼見帝。”王曰：“先生就舍，寡人聞命矣。”

Sū qín zhī chǔ, sān rì nǎi dé jiàn hū wáng. Tán zú, cí ér xíng, chǔ wáng yuē:"Guǎ rén wén xiān shēng, ruò wén gǔ rén. Jīn xiān shēng nǎi bù yuǎn qiān lǐ ér lín guǎ rén, céng bù kěn liú, yuàn wén qí shuō! " Duì yuē:  "Chǔ guó zhī shí guì yú yù, xīn guì yú guì, yè zhě nán dé jiàn rú guǐ, wáng nán dé jiàn rú tiān dì. Jīn lìng chén shí yù, chuī guì, yīn guǐ jiàn dì." Wáng yuē:  "Xiān shēng jiù shě, guǎ rén wén mìng yǐ. "

Another use of 之

• In this lesson 之 is used as a verb meaning 'to go to'.  蘇秦之楚 means 'Su Qin went to the State of Chu'.

The Passive Marker 乎

• The passive marker is used to form a passive construction. 乎 is one of the passive markers meaning 'by'. Its equivalent is 於.

說 used as a noun

• In this lesson,  說 in 願聞其說 is used as a noun 'explanation'. Many words can be both nouns and verbs. The grammatical context will determine the part of speech of a specific word. In this sentence, 聞 is the verb. It is followed by the object 其說 (your explanation).

Preposition 於

• 於 is a preposition. Its meaning in this lesson is 'than, as compared to'
• 楚國之食貴於玉 The food in the State of Chu is more expensive than jade.
• 薪貴於桂 The firewood is more expensive than cassia tree.