also: きによりてうおをもとむ
expression
using the wrong method leads to failure; asking for the impossible; climbing a tree to catch fish
Proverb of Chinese origin (Mencius). Used to criticize an approach that is fundamentally mismatched to the goal, making success impossible. The literal image is 'climbing a tree and seeking fish.'
See also: 木に縁りて魚を求む (きによりてうおをもとむ)
彼の計画は木に縁って魚を求むようなものだ。
His plan is like climbing a tree to catch fish—doomed from the start.
そんな方法では木に縁って魚を求むことになる。
With that method, you'll end up asking for the impossible.
From the Chinese classic Mencius, where it illustrates the futility of using a wrong method to achieve a goal. The Japanese form uses the archaic verb 縁る (to climb) and the classical conclusive form 求む.