In the concluding section of Letter Three in Tanya, the Alter Rebbe emphasizes the immense spiritual power of tzedakah, or charity. He illustrates this concept by likening charity to a coat of mail, a protective armor that shields the giver from negativity. Each coin donated is akin to a metal piece, meticulously crafted to form a barrier against harm. This act of giving not only safeguards the individual but also draws down divine, otherworldly energy from a higher realm, illuminating their life with blessings. The imagery of a helmet of salvation further reinforces the connection between our charitable deeds and the divine flow of grace, highlighting how our intentions can create an encompassing light that resonates throughout the universe. Engaging in charity becomes a transformative act, one that plants seeds of kindness, leading to abundant salvations that far exceed our expectations. The Alter Rebbe's teachings encourage us to recognize the profound impact of our actions, urging us to embrace the path of generosity and connection to the divine.