鱼沉雁杳

Explanation: Barrier than the Yushu Xin, news cut off. 　　Source: Tang Dai Shulun "Love Song" End of the World Road Fish Shen Yan Yao, the only letter parting human suffering. " 　　Examples: Source (Liu Yuan) out more than a year, ~. ★ Qing Wang Tao, "Song Liu Bin Suo, then return"