This is the first part of a translation of the story 鴻門宴 (The Feast at Hong Gate) from 史記 (Records of the Grand Historian). You can view the full original text of 史記 here.
又聞沛公已破咸陽，項羽大怒，使當陽君等擊關。 On hearing that Liu Bang had conquered Xianyang, Xiang Yu was extremely angry, and ordered the Dangyang Lord to attack Wu Pass. 沛公 = 劉邦
項羽遂入，至於戲西。 Xiang Yu thereupon entered the pass as far as Xixi.
沛公軍霸上，未得與項羽相見。 Liu Bang's forces were at Bashang, and he had not yet met with Xiang Yu.
沛公左司馬曹無傷使人 言於項羽曰： Liu Bang's Minister of War Cao Wushang sent someone to speak to Xiang Yu:
「沛公欲王關中，使子嬰為相，珍寶盡有之。」 "Liu Bang wishes to be ruler of the Guanzhong Plain, and make his son prime-minister; he has the necessary wealth for it." 王 here is read wàng, and is a transitive verb meaning “to rule over”.
項羽大怒，曰： Xiang Yu was extremely angry, saying:
「旦日饗 士卒，為擊破沛公軍！」 Tomorrow we will send soldiers to attack and conquer Liu Bang's army!"
當是時，項羽兵四十萬，在新豐鴻門， At that time, Xiang Yu's army numbered forty thousand, and was at Hong Gate in Xinfeng;
沛公兵十萬，在霸上。 Liu Bang's army numbered ten thousand, and was at Bashang.
範增說項羽曰： Fan Zeng tried to persuade Xiang Yu, saying: 說 here is read shuì, meaning “to persuade”.
「沛公居山東時，貪於財貨，好美姬。 "When Liu Bang lived east of the mountains, he was greedy for riches, and loved beautiful women. 山東 here is not a compound, i.e. it doesn’t refer to 山東 province. 好 here is read hào, meaning “to be fond of”.
今入關，財物無所取，婦女無所幸，此其志不在小。 Now he entered the pass, bringing now property or valuables, and no women; this shows that his ambition is not small.
吾令人望其氣，皆為龍虎，成五採， I had someone look at his _qi_; it is in all ways outstanding, and is complete; 五採 is 五色: “the five colours”, i.e. a complete set.
此天子氣也。 it is the _qi_ of an emperor.
急擊勿失。」 We must attack soon, and must not fail."