Musar על שבועות 59:8

One should also accustom himself to judge his friend in the scales of merit, as Chazal have said (Shevuoth 30a): "(Vayikra 19:15): 'In righteousness shall you judge your friend' — Judge your friend in the scales of merit." And this is one of the things for which one eats the fruits in this world, with the principal remaining for the world to come, as they said in Shabbath 127a.