לא תאמץ את לבבך ולא תקפץ את ידך מאחיך האביון. כי פתח תפתח את ידך לו ... (טו-ז,ח)
While reviewing these posukim, one cannot help but notice the replication of terms. The Torah admonishes us: Do not close your heart and your hand, but rather - "פתח תפתח" - open your hand. Why all this double-speak?
Additionally, what’s the function of the word "כי" in this context? Because “Open your Hand” doesn’t seem to make sense. (Rashi, as does Targum, explains this word כי to mean “rather”, which seems to be poshut pshat)
Perhaps we can say the following thought and derive a significant message. There are various ways to perform the mitzvah of tzedaka. Obviously, giving money is one method. But having an open home, providing rides for tzedaka solicitors, or even just giving them helpful advice, are also ways to provide for the poor. Even more meaningful could be a kind word, a warm smile, or an encouraging pat on the back. Says the posuk, if you have the means, don’t close your hand. But even if you cannot help monetarily to the extent you wish you could, at least, says the Torah, don’t close your heart, because that too is a means of tzedaka. "פתח תפתח" - you can open your wallet or your heart. (See Baal HaTurim here which inspired this idea.)
The Ohr HaChayim Hakadosh, too, refers to the word "כי", as a clarification - a reason not to close your heart. He explains that the Torah is teaching us an idea based on a posuk in Mishlei, "יש מפזר ונוסף עוד" (יא, כד). A person gives and receives. In other words, the pipelines of שפע is open for us when we give to others. Hence, don’t close your hand, because Hashem needs your hand to be ready to receive his myriad blessings, in return.
A number of posukim later, the Torah concludes with the words, "כי לא יחדל אביון מקרב הארץ". In other words, there will always be those in need and therefore, opportunities to lend a helping hand abound. If we view it as a privilege and offer assistance in any way we can, we will בעז"ה be zoche to unleash and receive incredible beracha from Above!