Speaking With Clarity of Mind:
When Rav Tzadok Hakohen of Lublin zy”a first started leading his flock (after the petirah of Rav Leibele Eiger zy”a) he accepted upon himself to remain silent and not to say divrei Torah in public. One year on the Shabbos of Parshas Beshalach, he opened his mouth and said Torah publicly for the first time. He explained the pasuk (Shemos 14:2): “And they returned and they camped in front of Pi Hachirus” by saying that this is a hint that before someone says a word, he must first weigh what he wants to say and contemplate if it is appropriate and worth saying. Thus, the pasuk is saying that one should “return and camp”, meaning that one should think with a clear mind “lifnei pi hachirus”, before using his mouth to say anything.
With this explanation, he was hinting that the reason he had been silent was because he wanted to ensure that he didn’t say anything inappropriate.
Rav Yosef Alter Hager of Rodovitch zy”a (quoted in Sefer Tiferes Sheb’malchus) uses this idea to explain the words in the beginning of this week’s Parshah: “In the midbar, in Aravah, opposite the Suf.” The word “midbar” can be understood as a reference to “dibbur” (speech), while the word “Aravah” can be a reference to a sharp (“areiv”) word. Thus, the pasuk can be read as saying that if one wants to say a sharp word, he should think about the “Suf” (“Sof”), the end of the matter. He should contemplate whether the end result of his words will be positive or negative.
