The Mishnah taught that a sukkah can be no more than 20 cubits high. Rabbi Judah, however, declared taller sukkot valid. The Mishnah taught that a sukkah must be at least 10 handbreadths high, have three walls, and have more shade than sun. The House of Shammai declared invalid a sukkah made 30 days or more before the festival, but the House of Hillel pronounced it valid. The Mishnah taught that if one made the sukkah for the purpose of the festival, even at the beginning of the year, it is valid.