坚如磐石

jiān rú pán shí

solid as a boulder (idiom); absolutely secure

rock-firm and unyielding

坚

jiān

strong

如

rú

as

磐

pán

firm

石

shí

abbr. for Shijiazhuang 石家莊|石家庄[Shi2 jia1 zhuang1], the capital of Hebei