Parshas Bishalach: Rav Naftoli MiRopshitz - When A Tzaddik Wishes You Only "Bracha V'Hazlacha"
When Bnei YisrAel were trapped at the Yam Suf, they confronted Moshe about the situation. Hashem told Moshe (Bishalach 14:15), "Ma Titzak Ailai; why are you screaming to me? Tell them to keep moving." Rashi says that we see from here that Moshe davened to Hashem. Rav Naftoli MiRopshitz (Zera Kodesh) asks, "Where do we see Moshe davened anywhere in the pasukim? What Tefila did he say?"
He answers that sometimes a person comes to a Tzaddik and pours out his troubles and asks the Tzaddik to daven for him. The Tzaddik sometimes answers with a short response of, "Hashem Yaazor," and the like. Why the callousness? He explains that sometimes the Tzaddik sees that it is a Shaas Kitrug, and the Satan has power to cause trouble. In this case he cannot daven openly because the Tefila will be stolen by the Satan. What he does is say a disguised hidden Tefila that is not noticed by the Satan, in the form of his short response. When a Tzaddik says even a few words, it is like a Tefila and it can be Poel Yeshuos.
At the Yam Suf, Moshe Rabbeinu saw that there was a Din hanging over Bnei Yisrael, as the Malachim cried to Hashem that we were not more worthy to be saved than the Mitzrim. Moshe responded, "Hisyatzvu U'Riu Es Yeshuas Hashem." That was his tefila. The powerful tefilos of a Tzaddik.