גָּמָל פּוֹרֵחַ בָּאֲוִיר

ביטוי (אנגלית)

Castles in the air/ a flying camel/ a flying pig/ nonsense

הגדרה (אנגלית)

By analogy: an imaginary or unreal thing (פּוֹרֵחַ means flying).

(What a vain oath it is to swear to change what is well known to man. He said about a pillar of stone that it is of gold, about a man that he is a woman, and about a woman that she is a man, swearing about something impossible: unless I have seen a camel flying in the air - Shavuot 3:9.)