The biblical expression 40 days and 40 nights just means a really long time.At the time among the Jews, the number forty wasn’t generally used to signify a specific number, per se, but rather more used as a general term for a large figure. When it was used in terms of time, it simply meant a “long time”. Thus, the phrase “40 days and 40 nights” was just another way to say a “really long time”.The number forty also had great symbolic meaning to the Jews and today among Christians and Muslims as well. The number forty to the Jews is a number that, when used in terms of time, represents a period of probation, trial, and chastisement (not to be confused with judgment which is represented by the number 9).As the product of 5 and 8, it also signifies grace (5) ending in revival or a new beginning (8). Thus, when 40 is referencing a period of probation, it also often coincides with the meaning derived from the factors 5 and 8. When it relates to enlarged dominion or extended rule, then it is related to the factors of 4 and 10, with 4 representing the creation of something and 10 representing perfection and completeness.