Meaning:

Literally translated as “the hardest scales,” this popular saying compares one’s best resources and most elite personnel to a dragon’s protective armor. This term was frequently used in media reports where doctors and nurses were sent from other Chinese regions to support Wuhan, the epicenter of the COVID-19 outbreak.

Example:

A: 这次抗击疫情全国各省市都派出了医疗队支援湖北。

Zhècì kàngjī yìqíng quánguó gè shěngshì dōu pàichū le yīliáoduì zhīyuán húběi。

All Chinese provinces and municipalities sent their medical teams to support Hubei Province.

B: 是的，大家都拿出了最硬的鳞。

Shì de，dàjiā dōu náchū le zuì yìng de lín。

Indeed. They sent their best resources and most elite personnel.