Do you know this expression???

[marysia_na]

Recently I've heard such expression "the mountain has brought forth the
mouse". Do you know what it means? I'm really curious about it.
Thanks in advance

[felusiak1]

Mozna po przełozyć na wysiłki nie przyniosły oczekiwanego/zapowiadanego rezultatu.

After two years of intensive research the only outcome was request for more money.
Thwe mountain labored and brought forth the mouse.

[jarka63]

Po polsku tak samo: góra urodzila mysz.

[marysia_na]

bardzo dziękuję!!! :)