2. "Rejecting the East and the North": It comes from the Romance of the Three Kingdoms, which means that because Wei was too powerful at that time, Zhuge Liang insisted on asking Liu Bei to make peace, forming an alliance with Sun Quan in the East and fighting Cao Cao in the North. It was Zhuge Liang's insistence on this policy that led to Battle of Red Cliffs's victory.
3. "Fire and water don't invade": It comes from The Romance of the Three Kingdoms and refers to Battle of Red Cliffs provoked by Cao Jun of Wei after the alliance between Shu and Wu. Zhuge Liang put forward a plan to burn Cao Ying on the Yangtze River. Eventually, due to the success of this strategy, 830,000 Cao Jun was destroyed by fire.
The extension of "taking the west of Sichuan", "rejecting the east and the west" and "fire can attack the water" all come from a pair of couplets, which depict Zhuge Liang's great achievements in his life through two simple couplets.
The whole sentence of the couplet is: close the two rivers, arrange eight arrays, catch six out of seven, light forty-nine lights before five feet, and concentrate on three concerns; Take western Shu, gather people from the south, and reject things from the north. In Zhong Jun's records, Jin Mu's divination was changed, and the water surface could be attacked by fire.
Similar to this couplet, other couplets about Zhuge Liang include:
Two watches, three cares, and a pair of feet.
Three worries in the grass, three points in the foot, and three meanings in the year of the fairy; Gentleman and minister are virtuous, brothers are United, and no one is like the later Han Dynasty.
Baidu Encyclopedia-Zhuge Liang's Classic Couplet