一根毫毛一根寒毛yī gēn háo máo

a hair from one’s arm (/body/head); the least little bit;in the least
❍ 我们也知道艰难的，但只俗话说的： ‘瘦死的骆驼比马还大’ 呢。凭他怎样，你老拔一根寒毛比我们的腰还壮哩！(《红楼梦》78)I know what difficulties are.But ‘A starved camel is bigger than a horse. ’ No matter how，‘A hair from your body is thicker than our waist.’/意见书也好，谈话会也好，我看看听听都可以，反正损伤不了～。(叶圣陶《倪焕之》107) Carry on with your theses and discussions;I don’t mind reading them and listening in; I’m perfectly immune to it all.

一根毫毛yī ɡēn háo máo

❶ 指身上极其微小的一部分。
❷ 比喻整体利益中的极小部分。也作“一根汗毛”。