Similarly, it is necessary to fulfill this mitzvah of loving friends in a manner of “doing good” in both speech and deed. Doing good in speech means to speak positively about good things that make people happy, such as good tidings and helpful advice. Or to remove obstacles from the friend’s path, such as to inform him of some impending damage he might suffer or the like. And: to console him when he is suffering.
In deed means to physically perform acts of kindness with one’s body or possessions. Whatever one would want others to do for him, or to have compassion on him, so he should do for others in order to fulfill the mitzvah of Love your fellow as yourself (Vayikra 19:18). The more one pushes himself in his efforts on behalf of his fellow, the greater will be his reward and will he bring pleasure to his Creator, [so to speak]. For “we are all but the children of one Father” (cf. Bereishis 42:11) — we are all brothers; just as a person cares deeply about a single one of his limbs, so must we care about every single Jew, for we are like a single person in a single body.