He must crack the nut that would eat the kernel.

Someone who wants a reward must first do the work needed to obtain it. The kernel is worth having, but it cannot be enjoyed while the shell remains intact.

The proverb places responsibility on the person who hopes to benefit. It presents an inconvenient task not as a reason to give up, but as a necessary step toward the desired result.

Use this proverb to encourage someone to tackle a necessary obstacle before expecting a benefit, or to remind a person that wanting a result does not remove the work required to achieve it.