• Changing one’s clothing depending on the task

Rav Acha bar Abba said in the name of Rebbe Yochanan that the Torah source for the appropriateness of changing one’s clothing to suit the task at hand, comes from a passuk in regards to removing the ashes from the mizbeiyach. It states,ופשט את בגדיו ולבש בגדים אחרים – He shall remove his garments and don other garments, meaning, he needed to put on different garments to bring out the ashes, a less important task.

Rashi explains that Hashem considers it honorable to wear nicer clothing for an exalted purpose , and therefore, it is appropriate to change out of them before performing menial tasks.

It was taught in the academy of Rebbe Yishmael that this teaches us derech eretz, that garments 

that one has worn when he cooked a pot of food for his master should not be the garments he wears when pouring a cup of wine for his master. Cooking the food is a metaphor for clearing the ashes, and pouring the cup represents the libations on the mizbeiyach.

• Criteria for a talmid chochom to be appointed a community leader

Rebbe Yochanan stated that the criterion for a talmid chochom to be appointed a leader over the community is that he should be able to answer a question from any place in Shas, even from Masechta Kallah.

Masechta Kallah is a series of Baraisos that is one of the minor Masechtos that are not typically learned unless one has mastered Shas. It can be found after Avos. The opening halacha teaches that a kallah that has not had the berachos of nisuin recited yet, is forbidden to her husband like a Niddah.

• Yom Kippur leniency of trimming vegetables in the afternoon

In a discussion regarding why the customary shofar blasts blown on erev Shabbos were not blown on a Yom Kippur that fell out on erev Shabbos, the Gemara points out that Yom Kippur had a Rabbinic leniency that permitted people late in the afternoon on Yom Kippur to trim the outer, spoiled leaves from stalks of vegetables (קניבת הירק), in preparation to chop or cut them after Yom Kippur. This was permitted even though Rabbinically one is typically forbidden to make preparations for a weekday.

Rashi explains that the Rabbis were lenient because the food preparation late in the day when a person is hungriest increases the distress of fasting, which is a fulfillment of the mitzvah, ועניתם את נפשתיכם - and you shall afflict your souls. 

Siman – Kiddie (Amusement) Park. At the kiddie park where children got to wear special ash removal clothing and dress up as Rabbis answering questions, lunch was served late in the day, after the outer, spoiled leaves of vegetables got trimmed. Key Words – changing clothing, answering questions, trimming vegetables