In addition to the five prohibitions that apply on Tisha Be-Av, there are other prohibitions that are connected to the fact that Tisha Be-Av is a day of mourning. Just as a mourner may not study Torah during the shiva period, one may not study Torah on Tisha Be-Av, so that one’s attention is not diverted from the mourning. Another reason one may not study Torah during a period of mourning is that Torah study makes one happy, as it says, "The precepts of the Lord are just, gladdening the heart" (Tehilim 19:9). One may not even think thoughts of Torah, because even that makes one happy. However, it is a mitzva to study sad sections of the Torah, which deal with the calamities that befell Israel and the afflictions that man encounters, as these sections are appropriate for the mood of the day. One should not study even these sections in depth, because such study makes one happy. However, if one thinks of a novel idea while studying a matter superficially, he does not need to worry, because that is the nature of learning (ahs 554:4). In addition, if one thinks of a significant idea and is worried that he may forget it by the end of the fast, he may write it down in shorthand (see Kaf Ha-ĥayim 554:110).

One may study the following topics. In Tanakh, one may study the chapters that describe the destruction of the Temple, which are found in the books of Melakhim, Divrei Ha-yamim, and Eikha. One may also study the prophecies of the destruction, which cover most of the book of Yirmiyahu, part of Yeĥezkel, and small portions of Yeshayahu and the books of Trei Asar. However, one should not study the prophecies that predict the calamities and destruction that will befall wicked nations, as these cause us joy. One may study the book of Iyov, which deals with suffering, but one should not study the end of the book. One may also study the sections of admonition and calamity in the parshiyot of Be-ĥukotai, Ki Tavo, and Ha’azinu. In all of these cases, one may study the verses with commentary, in order to understand the simple meaning of the passage, but not in order to delve deeply into the content.

Regarding the aggadic sections of rabbinic literature, one may study the passages dealing with the destruction of the Temple in Gittin 55b-58a and most of Midrash Eikha Rabba, skipping the midrashim that deal with consolation. One may also study the third chapter of Mo’ed Katan, which deals with the laws of mourning and excommunication, as well as the sections at the end of Ta’anit that discuss the laws of Tisha Be-Av.

Regarding halakhic topics, one may study the laws of the Three Weeks and Tisha Be-Av (sa oĥ 550-561), as well as the laws of mourning (sa yd 334-403). If a rabbi receives an urgent question in an area of halakha that one may not study on Tisha Be-Av, he should answer it without explaining his reasoning (mb 554:5).

One may study ethical and moralistic works on Tisha Be-Av, even though they quote biblical verses and rabbinic statements, because their whole purpose is to inspire a person to repent for his sins. Therefore, the regular joy one feels when learning Torah is not present.¹³

Ideally, one should begin to observe these laws from midday on the day before Tisha Be-Av. However, as we already learned, if one feels that limiting his Torah study to these specific topics will curtail his study, he should study whatever his heart desires until Tisha Be-Av begins (Rema 553:2; mb ad loc. 8; above 9:3).

One may not read exciting books or newspapers, or study other disciplines on Tisha Be-Av, so as not to divert one’s attention from mourning (ahs, yd 384:9). However, it is permissible, and even fitting, to read history books about the destruction of the Temple, the exile, and the hardships that have befallen the Jewish people.