because judgment without mercy will be shown to anyone who has not been merciful. Mercy triumphs over judgment.
OJBFor the Din (Judgment) will be without rachamim (mercy) to the one not having shown rachamim. Rachamim wins the nitzachon (victory) over HaDin.
RVFor judgment is without mercy to him that hath shewed no mercy: mercy glorieth against judgment.
TCENTFor judgment is without mercy to anyone who has not shown mercy; mercy is exalted over judgment.
T4TSpeak and act like that, because when God judges us, he will not act mercifully toward those who do not act mercifully toward others. But when we are merciful to others, we can rejoice, because our being merciful shows that we are acting like people whom God has mercifully saved from being judged (OR, we can rejoice because God will judge us mercifully).