Arachin 9 - 15
- Fixing the length of months in the lunar year
- The varying length of the lunar year
- The instruments used for music in the Beit Hamikdash
- The days of the year in which full Hallel is said
- Why no Hallel is said on Rosh Hashana, Yom Kippur and Purim
- The failure of improvements in the Beit Hamikdash
- Who played the instruments for the song which accompanied the sacrifices
- Simcha and gladheartedness
- When Levites switch roles in their service
- The timing of the destruction of the Beit Hamikdash
- How many Yovel (fiftieth year celebrations) were there between entry into Eretz Yisrael and exile
- The number of musical instruments and Levites playing them
- The dangers of lashon hara (gossip and slander)
Not So Smart
Are improvements always successful?
The gemara records improvements made in the Beit Hamikdash which proved to be counterproductive. These included musical instruments used by the Levites for providing the musical accompaniment to sacrifices, a tool used for preparing the spice sacrifice and the flow of water from the Shiloah Pool.
The lesson to be learned from the failure to these improvements is the fulfillment of the warning of the Prophet Yirmiyahu that "Let the wise man not laud himself with his wisdom" (9:21). Rashi explains that the vessels of the first Beit Hamikdash were all created according to Divine instructions so that any attempt to improve upon them was an exercise in futility.
- Arachin 11a
What the Sages Say
"One who speaks lashon hara is guilty of sin comparable to the three cardinal sins of idol worship, murder and sexual immorality."
- The Yeshiva of Rabbi Yishmael - Arachin 15b
