"When you will lend money to a poor person who is with you" (Shemos 22:24). Look at yourself as if you are the poor person (Rashi).
One cannot properly fulfill the mitzvos of tzedaka and chesed unless one establishes a strong sense of unity with the recipient. If one looks down on the poor, or is emotionally detached, the mere giving of money is only an incomplete mitzvah.
"Any gazing (hashkafa) in Scripture produces bad results, except for 'gaze from your holy abode', for great is the power of gifts to the poor" (Rashi Breishis 18:16). Why is hashkafa negative, and how does tzedaka transform it into a positive force?
The targum of the word "chabura - bruise" (Shemos 21:25) is mashkofi, an expression of beating. Similarly, the Hebrew word for lintel is mashkof, because the door beats against it (Rashi). Hashkafa (gazing), which is etymologically related to mashkofi, indicates an adversarial relationship; one gazes upon another, not upon himself. When we look at others as adversaries, "looks can kill", just as a physical blow can cause a bruise.
The only antidote to the hostility inherent in gazing is the unity of tzedaka. If we look at ourselves as if we are the poor person, if we overcome the adversarial relationship that typically exists between two people, Hashem's gaze upon us is transformed into a blessing.
"Do not take revenge nor bear a grudge against a member of your people, love your friend as yourself "(Vayikra 19:18). If one cut his left hand with his right, would he take revenge by then cutting his right hand? So, too, if you love your friend as yourself, as a part of you, you will not take revenge (Yerushalmi Nedarim 9:4, cited by Netziv).
Just as we must look at ourselves as if we are the poor person, so too must we relate to our friend as if he is a part of us. This unity is the true fulfillment of tzedaka and ahavas Yisroel.
When kohanim complete the Birchas Kohanim (Priestly blessings) they say, "Master of the world, we have done what You have decreed, now may You also do as You have promised us: Gaze from your holy abode and bless Your people." A kohein must bless those present with love (be'ahava). This love, like proper tzedaka, results in the unity which transforms hashkafa, which is usually adversarial, into a heavenly blessing.
In a world of adversarial relationships, of banging and bruising, of looks which can kill, we are commanded to achieve unity between donor and recipient, blesser and blessed. By viewing and loving others as part of ourselves, we can transform negative forces into positive ones, and merit Hashem's bracha.