The Baal HaTanya (Iggeret HaKodesh 4) explains Mosheh Rabbeinu's comments in the Torah (ומלתם את בשר לבכם) to explain that we must remove the thick outer foreskin of our hearts, to learn to love HaShem, and in turn he will remove the finer casing around our hearts, and reveal our inner essence to his light. He says that Tzedaka is the best way to hasten this process.
We see, sadly, in this day and age just how close money can get to our hearts. Bills can pile up and cause physical pain, serious stress on our fragile hearts. The best way to combat this reality is to give tzedaka. In a way through tzedaka we are putting our money where it can't be touched by anyone..we are putting it in the only sure-fire investment. Every cent or agurah that goes to tzedaka is a scale in the armor that protects us in this world and the next.
Why did Mosheh pray to HaShem through the language of ואתחנן? It seems to me to be language that relates to tzedaka and begging. Mosheh was pouring out his heart, appealing to HaShem's midah of Tzedaka, knowing that since Tzedaka is the deepest power we have, it is also the most powerful of HaShem's midoth.
Let's give tzedaka to awaken HaShem's tzedaka and bring peace to all of klal Yisrael.