Wherein Shall be Explained the Greatness of The Merit of the Person who Judges his Fellow Favorably
A person should also accustom himself to judge his fellow favorably, as our Sages of Blessed Memory have said [in maseches Shavuos, 30a): ““With righteousness you shall judge your nation.” (Vayikra: 19; 15) – Judge your fellow favorably.” [Judging a fellow Jew favorably] is one of the things for which a person eats the fruits [of their reward] in this world, and the principle [of the reward] remains for him in The World to Come, as [our Sages] have said in [maseches] Shabbos (127a).
This matter of judging [one] favorably, applies whether one can determine with regard to the mater itself, that it was heard about [the person in question] that he did or said [something, that would indicate] that the judgment accords with him, or that he committed this matter out of negligence, or that he was unaware of the severity of the [given] prohibition. Even if it were to become clear that all of the explanations [that are favorable] are not applicable to this incident, he should think [as follows]: “Perhaps [the person] who related [this incident] left out one detail, or added one small detail, which changed the incident [from what truly occurred, and it thereby reflects] shamefully upon the [person who was discussed]. Our Sages of Blessed Memory have said [the following] rule in [Pirkei] Avos (Chapter 2, Mishna 4): “Do not judge your fellow until you reach his place.”
 The gemara states as follows:
“Our Rabbi taught [in a Baraisa], ““You shall juudge your nation with righteousness.” (Vayikra: 19; 15) That one person [of those being judged] shouldn’t sit [while] the other one stands. One [shouldn’t] say all that he needs [to say, while the other presents] a summary of his statement. Another explanation: ““You shall judge your nation with righteousness.” – Judge your fellow favorably. Rav Yosef taught, “You shall judge your nation with righteousness.” – [This refers to] the nation that is with you in [observance of] Torah and mitzvos, [you shall] him well.”
RaSh”I explains that judging those who observe the Torah and mitzvos “well”, refers to a situation where a judge has two cases comes before him, one of which involves Torah scholars. In such a situation, the judge should give precedence to the case involving the Torah scholars, judging them first.
 The gemara in maseches Shabbos states as follows:
“Rav Yehuda the son of Shaila said in the name of Rav Asi who said in the name of Rabbi Yochanan: “[For] six [mitzvos], a person eats the fruits [of the reward] in this world, and the principle [of the reward] remains [intact] for him for The World to Come. [These six things are as follows]: Inviting guests, visiting the sick, concentration in tefillah, and arising early to come to the Beis Midrash (Torah study hall), and those who raise their children for the study of Torah, and one who judges their fellow favorably…”
 This teaching quoted from Pirkei Avos was stated in the name of Hillel and is one of a number of teachings quoted from Hillel in this section of Pirkei Avos. The above teaching from Hillel is coming to teach us that a person should not judge his fellow as being guilty upon seeing him come to be tested and stumbling in that test until personally experiencing a similar test and does not stumble in it, rather, successfully overcomes it.