Keri’ah for our teachers TB Moed Katan 26

Today's daf TB Moed Katan 26 cites 11 occasions when we are obligated to do keri'ah (קְרִיעָה), rendering our clothes, and we are forbidden to repair the tear professionally "And these are the rents of mourning that may never be properly mended: One who rends his garments for the death his father, or for his mother, or for his teacher who taught him Torah, or for the Nasi, or for the president of the court; or upon hearing evil tidings; or hearing God’s name being blessed, which is a euphemism for hearing God’s name being cursed; or when a Torah scroll has been burned; or upon seeing the cities of Judea that were destroyed or the destroyed Temple or Jerusalem in ruins. This is the way one conducts himself when approaching Jerusalem when it lies in ruin: He first rends his garments for the Temple and then extends the rent for Jerusalem." (Sefaria.org translation)

We understand the symbolism of this law when it comes to our parents. Why are our teachers included in this list? Teachers like parents play an ultimate role in the child's life. Our tradition teaches us that the mother and father bring the child into this world and by the virtue of the Torah the teacher teaches the teacher brings the child into the next world. “his father brought him into this world, and his teacher, who taught him the wisdom of Torah, brings him to life in the World-to-Come. ” (TB Baba Metzia 33a, Sefaia.org translation)

Tosefot ד"ה וְעַל רַבּוֹ שֶׁלִּימְּדוֹ תּוֹרָה on TB Moed Katan 25b asks how much Torah does the teacher need to teach in order to obligated keria'ah? They cite the Gemara in TB Baba Metzia 33a where Rabbi Yehuda and Rabbi Yosei are disagreeing. "Rabbi Yehuda says: The reference is to any teacher from whom one learned most of his knowledge, be it Bible, Mishna, or Talmud. Rabbi Yosei says: Even if he enlightened him in the understanding of only one mishna, that is his teacher." (TB Baba Metzia 33a, Sefaia.org translation) Ulla draws the conclusion based on Rabbi Yosei’s position “Ulla says: The Torah scholars who are in Babylonia rise in deference before one another and rend their garments in mourning over one another’s passing. In contrast to Eretz Yisrael, where the preeminent Torah scholars and teachers served at the heads of the Torah academies, in Babylonia most scholars studied Torah with peers and there was no preeminent teacher.” (Ibid.) Rebeinu Hannaniel says the halakha is according to Rabbi Yosei. The Sheiltot of Rabbi Akhai poskins according to Rabbi Yehuda. Nevertheless,Tosefot cites more support for Rabbi Yosei's position than Rabbi Yehuda’s..\

I’ll let the Shukhan Arukh have the last word for now. "All the ways it is said that one must honor (the deceased teacher) only apply to the person's outstanding teacher who taught him most of his knowledge whether it is in Bible study, Mishna, or, Gemara.

(The Rama comments: Pipul teachers s not considered part of the list of rabbis we honor thusly, Only those teachers teachers Jewish law, deep study based on truth and righteousness.)

However the teacher did not teach the person the majority of his wisdom, one is only obligated to honor him by coming within four amot and doing keri'ah as he would for all the other relatives.” (Yoreh De’ah, 422: 25ff, my translation)