From Wang Changling's 《
芙蓉楼送辛渐》 (Tang dynasty), sending off his friend Xin Jian at Furong Tower:
洛阳亲友如相问,
一片冰心在玉壶。 Wang Changling had been demoted and slandered; the line is his reply to gossip — tell the Luoyang friends my integrity is intact.
冰心 (ice-heart) later became the pen name of modern writer Xie Wanying (1900–1999).