The mountain begot a mouse
By metaphor: an event that began in an impressive form or with many expectations ended in a minor way. The expectation for something great ended with nothing.
(Modern Hebrew)
Translation
Expression (Hebrew)
הָהָר הוֹלִיד עַכְבָּר
Definition (Hebrew)
בְּהַשְׁאָלָה: הָאֵרוּעַ שֶׁהִתְחִיל בְּצוּרָה מַרְשִׁימָה אוֹ עִם הַרְבֵּה צְפִיּוֹת הִסְתַּיֵּם בְּצוּרָה מִינוֹרִית. הַצִּפִּיָּה לְדָבָר גָּדוֹל הִסְתַּיְּמָה בְּלֹא כְלוּם.
(הָעִבְרִית הַחֲדָשָׁה)