骏马面前无沟壑怂人面前全是坎
[jùn mă miàn qián wú gōu hè sŏng rén miàn qián quán shì kăn]
It contrasts bravery with cowardice by comparing riding a horse (where no ditch too big to leap) with a fearful person facing challenges (every situation seems insurmountable obstacles), implying admiration for courage and bravery and disapproval toward weakness and retreat mentality.