When Yang Guozhong (楊國忠 - 양국충) was Head of the Legislative Bureau (右相 - 우상), during the Tang Dynasty, he had so much authority that he was compared to Mount Tai (泰山 - 태산), one of China's "five sacred mountains" (五嶽 - 오악). People hoping to enrich themselves gathered around him, but a man named Zhang Tuan (張彖 - 장단) was not so easily convinced. The following is a 752 A.D. entry in the "Zizhi Tongjian" (資治通鑑 - 자치통감), which is where the old saying 冰山難靠 supposedly originated.
或勸陝郡進士張彖謁國忠曰, "見之, 富貴立可圖."
Someone (或) advised (勸) a palace graduate from Shan Commandery (陝郡進士) [named] Zhang Tuan (張彖) to visit (謁) Guozhong (國忠), saying (曰), "[If you] meet (見) him (之), riches (富) and honors (貴) immediately (立) can (可) be obtained (圖)."
彖曰, "君輩倚楊右相如泰山. 吾以為冰山耳. 若皎日既出, 君輩得無失所恃乎?"
Tuan (彖) said (曰), "You guys (君輩) rely on (倚) Legislative Head Yang (楊右相) as if (如) [he were] Mount Tai (泰山). I (吾) consider [him] (以為) an ice mountain (冰山) only (耳). If (若) the bright (皎) sun (日) is out (既出), [won't] you guys (君輩) get (得) nothing (無) [and] lose (失) what you rely on (所恃乎)?Notes
進士 - palace graduate; someone who has passed the highest level civil service exam
陝郡 - Shan Commandery
既出 - already (既) came out (出)
The entry was recorded in 752 A.D. - 唐紀 (당기) 玄宗天寶十一年 (현종천보 12년)