It is just like English sayings and phrases, there are Japanese sayings and phrases as well. It is called [kotowaza ことわざ].
Today’s kotowaza
果報は寝て待て。Good things come to those who wait/sleep and wait for good luck.
KAHO – luck, good fortune, happiness.
NERU – to sleep
MATSU – to wait

Its meaning
Good things comes naturally. We can not do anything so we just need to wait patiently.
An example
Turi ni itta toki, ojisann ha “Kaho wa nete mate dayo” to itte, hontou ni hirune o shinagara sakana o matte ita.
When I went to fishing with my ancle, he said “kaho wa nete mate” and he was really sleeping while he was waiting for a fish.

arigato