We see that Moshe davens for his sister, Miriam, after she gets tzoras. Moshe Rabeinu davens to Hashem, saying: “?-?, ?? ??? ?? ??” The Nachal Kedomim says that this special secret of davenin which Moshe Rabbeinu received from shamayim. This received secret is that if one says the word ?? twice, Hashem will answer their tfillos in the affirmative.
Using this we can also understand the exchange between Moshe Ranneinu and Hashem in the beginning of Parshas ??????. Daving to enter Eretz Yisroel, Moshe asks Hashem “?????-??, ????? ??-???? ?????, ???, ???? ?????” to which Hashem replies “??-???? ??? ??? ???, ???? ???” Moshe in his davening says the word ??, therefore Hashem replies ??-????, don’t add ???? ??? in this which you have already said, i.e. don’t say the word ?? a second time.
In the introduction to the sefer Mordechai L’Rav Ashkenazi it says that the reason for this is because the word ?? in gemartia (when doubled, since we are saying it twice) is equal to ?????