Mussar sobre Provérbios 17:17

It is taught in Tractate Avot 1:6, "Acquire for yourself a friend." Our Rabbis, may their memory be blessed, also said (Taanit 23a:17), "Either friendship or death." The wise one (Shlomo) has said that a person without a friend is like a left without a right. And the pious Rabbenu Yonah wrote, "The paths to repentance require a friend with whom to speak if one errs about the processes of repentance, in order to reprove one another and in order to investigate how to be saved from sin. About them it is stated (Malachi 3:16), 'Thus those who fear the Lord have spoken, each person with their companion, etc.'" To here are [his words].

And similarly one must fulfill the mitzvah of “and do good” in speech and in action. In speech, [one should] say good and proper things to make people happy: for example, by sharing good news, giving good advice, and removing obstacles from another person’s path, [i.e.] by informing him if one becomes aware that any harm may befall him in any way, and comforting him in his time of distress, and many other similar things. And in action, one should perform acts of kindness, both physically and financially. Just as one would want others to act for him, and to have mercy upon him, and inconvenience themselves to have mercy on him, likewise he should act in order to perform acts of kindness and fulfill the mitzvah of loving your neighbor as yourself. “Happy is the man who does this and the son of man who lays hold on it” (Isaiah 56:2). “According to the pain is the reward” (Avot), for according to the pain one gives satisfaction to his creator. And just as a father has compassion on his children and “a brother is born for adversity” (Proverbs 17:17) [see Rashi there for what this means], so too each person should help his fellow, for “we are all one man’s sons” (Genesis 42:11); we are brothers. And just as one cares for one of his limbs, so to one must care for every person of Israel, for all of us are like one person; like one body.