1,392. Leaving a "Zecher L'Churban" in One's Home

Hilchos Taaniyos 5:11

Torah scholars should not greet people on Tisha b’Av. Rather, they should sit in pain and anxiety like a person in mourning. If an unlearned person should happen to greet them, they should reply but in a muted, serious tone. We are not permitted to read from books of the Torah, Prophets or Writings on Tisha b’Av, nor to study Mishna, halacha, Gemara or Aggadah. One may only study the books of Iyov (Job), Eicha (Lamentations) and the prophecies of retribution in the book of Jeremiah. Children should not learn Torah in school on Tisha b’Av. Some scholars do not wear the tefillin of the head.

Hilchos Taaniyos 5:12

After the Temple was destroyed, the Sages of that generation decreed that we may not erect buildings with walls ornately decorated like royal palaces. Rather, one should coat the walls of his home with mortar and paint them with lime, leaving a one-cubit square unpainted opposite the door. If someone buys a house with decorated walls, it may be left alone. A person need not scrape the walls of such a house.