Second-to-last line of Wang Changling's (
王昌龄, Tang dynasty) 《
芙蓉楼送辛渐》 ('Farewell to Xin Jian at Hibiscus Tower'):
寒雨连江夜入吴,
平明送客楚山孤。
洛阳亲友如相问,
一片冰心在玉壶 — 'Cold rain joined the river entering Wu at night; at dawn I saw my friend off, the Chu mountains lone. If kin and friends in Luoyang ask after me, tell them my heart is a piece of ice in a jade jug.'