Ethics of the Fathers: Chapter 4 Mishnah 9 (1)
Rabbi Yishmael, son of Rabbi Yose, says: One who withdraws from judgement removes from himself hatred, robbery and the responsibility for an unnecessary oath. But one who is too self-confident in issuing legal decisions is a fool, wicked and arrogant of spirit.
Avot 4:9
Ethics of the Fathers: Chapter 4 Mishnah 9 (2)
Rabbi Yishmael – his recall of Scripture was so precise that it was claimed that one could write a Torah scroll based on his dictation.
Talmud Yerushalmi, Megillah 4:1
Ethics of the Fathers: Chapter 4 Mishnah 9 (3)
One who withdraws from judgement – Disputants should attempt to compromise and engineer an out-of-court settlement rather than allow their case to go to trial.
Rashi
Ethics of the Fathers: Chapter 4 Mishnah 9 (4)
Removes from himself hatred – By arranging an amicable compromise, both of the parties will conclude the case without harbouring animosity toward each other.
Rashi
Ethics of the Fathers: Chapter 4 Mishnah 9 (5)
Robbery – A litigant may be tempted to bend the facts, thus robbing his adversary of his rightful property. Compromise enables one to avoid this kind of larceny.
Rashi
Ethics of the Fathers: Chapter 4 Mishnah 9 (6)
And the responsibility for an unnecessary oath – Convinced of the correctness of his position, a litigant may be tempted to swear falsely, thus violating one of the Ten Commandments.
Rashi
Ethics of the Fathers: Chapter 4 Mishnah 9 (7)
One who is too self-confident in issuing legal decisions – This refers to one who has no fear of ruling incorrectly and who does not take the time or patience to investigate the matter thoroughly, wielding all the arguments again and again.
Rashi
Ethics of the Fathers: Chapter 4 Mishnah 9 (8)
A fool – A person who is wise in his own eyes is the ultimate fool, for he will never repent.
Rabbeinu Yonah
Ethics of the Fathers: Chapter 4 Mishnah 9 (9)
Wicked – Someone unafraid to issue erroneous rulings and unconcerned that he may cause others to lose their money or swear falsely is a wicked person.
Tiferet Yisrael
Ethics of the Fathers: Chapter 4 Mishnah 9 (10)
Arrogant of spirit – Here is a note of caution to anyone who tries to rule for himself on personal Halachic questions rather than seeking competent counsel. It is an exaggerated sense of self-importance and vanity that keeps him from consulting a competent authority in the first place.
Mikveh Yisrael