it is raining cats and dogs, the windows of heaven were opened
Figuratively: A heavy downpour fell (originally, 'aruba' means an opening).
("On that day all the fountains of the great deep burst forth, and the windows of heaven were opened" – Genesis 7:11, describing the Flood)
Translation
Expression (Hebrew)
אֲרֻבּוֹת הַשָּׁמַיִם נִפְתָּחוּ
Definition (Hebrew)
בְּהַשְׁאָלָה: יָרַד גֶּשֶׁם שׁוֹטֵף (אֲרֻבָּה בַּמָּקוֹר מַשְׁמָע פֶּתַח).
("בַּיּוֹם הַזֶּה נִבְקְעוּ כָּל מַעְיְנֹת תְּהוֹם רַבָּה וַאֲרֻבֹּת הַשָּׁמַיִם נִפְתָּחוּ"- בְּרֵאשִׁית ז יָא, תֵּאוּר הַמַּבּוּל)