Why does Moshe say K'Chatzos (about midnight)?? Usually Hashem is so precise and The Torah doesn't like to waste words and letters so why does It say About midnight???
Rashi says that usually Hashem is accurate. (in Bereishis when he is creating the World he uses the word B'chatzos (at midnight exactly). So again we still have the question, why is the Torah not exact here??
Rashi also says that Pharoah's astrologers weren't so accurate and may have erred which would cause pharoah to call moshe a liar and therefore it may be a disproof of Hashem.
So Hashem tells Moshe to say K'Chatzos in order that should the astrologers make a mistake it won't make anyone look like a liar!!
There is a mishna in Pirkei Avos that has a lesson that can be derived from this posuk.
The mishna states say little and do much, In this possuk Hashem has said little and done much!! He said he will do it at about midnight and didnt promise anything however He knew full well that He would do much and do it at B'Chatzos exactly midnight!!!
Heres our lesson, Say little and do much!!