DEUT646 "You must not harden your heart nor close your hand [to your destitute brother]" [Devarim 15:7]. We have been admonished to remove from our soul the quality of cruelty and to implant within it pleasant saplings [Yeshayahu 17:10]. --The faithful [virtues of] mercy and kindness, as the pasuk states (ibid. 28:9), "Walk in His ways."[I.e., Just like Hashem is merciful, so too you should be merciful (Sha'arei Teshuvah Hameforash)]. Since it is possible for one to not be tightfisted and show grace to the poor, but without being merciful, as the pasuk states (Mishlei 12:10), "The mercy of the wicked is cruelty" [I.e., Even his acts of mercy are expressions of cruelty and haughtiness (Rabbi Yonah, ad loc.)] Therefore the pasuk states, "You must not harden your heart." The punishment for acting cruelly is harsh and bitter, as will be explained in The Gate of Cruelty [see the First Gate, note 97], God willing. Furthermore, our Sages, z"l, said (Shabbos 151b), "He will grant you mercy ["That you should be merciful to others" (Rashi)], be merciful to you, and have you multiply [this verse]--whoever is merciful to his fellow creatures will be treated mercifully by Hashem; and whoever is not merciful to his fellow creatures will not be treated mercifully by Hashem."