Likutei Moharan 57:7/ליקוטי מוהר"ן נ״ז:ז׳

17. Know, too, that to eliminate and subdue the enemy, either fasting or Shabbat eating is enough on its own. But for an abundance of peace it is necessary to increase charity, as in the teaching of our Sages, of blessed memory: The more charity, the more peace (Avot 2:7). And this is what they said: The reward for fasting is charity (Berakhot 6b). And they said: Sun on Shabbat is charity for the poor (Taanit 8b). “Sun” is the aspect of peace, as in the teaching of our Sages: “the sun shone upon him” (Exodus 22:2)—just as the sun brings peace to all the world’s inhabitants… (Mekhilta, Mishpatim 6). This is: “Sun”—i.e., peace—is achieved only by means of “charity to the poor.”