By: Rabbi Ari Enkin
Contrary to popular misconception, the Three Weeks of mourning do not end with the conclusion of Tisha B’av. In many ways they actually extend into the 10th Av. As we will see, the 10th day of Av is actually quite significant, and in many ways, it is an extension of Tisha B’av itself. In fact, there was once a custom to fast on both the 9th and 10th of Av  and it seems that there were those who did so as late as the 15th century and perhaps even the 17th century. Although there is no one today who fasts on both the 9th and 10th of Av “because we are too weak to do so”, a certain measure of mourning is observed on the 10th of Av. One who for whatever reason did not fast on the 9th of Av should fast on the 10th of Av, as well as observe all the other Tisha B’av restrictions.
There is much discussion as to exactly when the first Beit Hamikdash was destroyed. According to one account it was destroyed on the 7th of Av while according to another it was destroyed on the 10th of Av. In order to reconcile this contradiction, the Talmud suggests that on the 7th of Av the Babylonians entered the Beit Hamikdash and went on a rampage which continued for three days. On the afternoon of the 9th of Av they set fire to the Beit Hamikdash which culminated in its destruction.
Similarly, there is also some discussion as to when the second Beit Hamikdash was destroyed. According to the Talmud it was destroyed on the 9th of Av while according to Josephus it was destroyed on the 10th of Av. Based on this and other considerations, there have been sages in the past who advocated moving the fast from the 9th of Av to the 10th. Indeed, although the fires were set on the 9th of Av, they were set late in the afternoon, and hence most of the destruction of the Beit Hamikdash actually took place on the 10th of Av.
According to the Shulchan Aruch one may not eat meat or drink wine on the 10th of Av. Ashkenazi custom is to observe these restrictions only until midday on the 10th of Av. So too, while there are authorities who permit one to cut one’s hair and do laundry immediately after the fast common custom is to refrain from these activities until midday on the 10th of Av, as well. Nevertheless, under extenuating circumstances one may be lenient and do laundry immediately after the fast. One is also permitted to shower after the fast should one feel the need to do so.
When Tisha B’av falls out on Thursday, however, it is completely permissible to do laundry and take a haircut immediately after the fast is over in honor of Shabbat. Nevertheless, eating meat, drinking wine, and listening to music remain prohibited until midday on Friday. When Tisha B’av falls out on Shabbat and is pushed off to Sunday, all the restrictions of the nine days are permitted immediately after the fast with the exception of eating meat and drinking wine. Some refrain from marital relations on the night of the 10th of Av unless it is the night of tevilla.
It is interesting to note that there were those who held that some of the mourning restrictions continue for the entire month of Av! For example, Rav Papa was of the opinion that the ban on not scheduling a court appearance with a non-Jew applies for the entire month of Av. So too, in some communities, weddings were not held the entire month of Av, or at least until after Shabbat Nachamu. Indeed, there was a custom, observed by no less an authority than Rashi, to observe all of the restriction of the Nine Days until Shabbat Nachamu. Rav Yehuda was of the opinion that the prohibition against doing laundry and taking a haircut continue for the entire month of Av, as well.Nevertheless, the halacha is not in accordance with any of these views.
1 Yerushalmi, Taanit 4:6.
2 Beit Yosef, OC 558.
3 Magen Avraham 558:2.
4 Tur, OC 558.
5 Birkei Yosef, OC 558.
6 Melachim II 25:8,9.
7 Yirmiyahu 52:10.
8 Taanit 29a.
9 Taanit 29a.
10 Josephus, War of the Jews 6:4:5.
11 Taanit 29a; Tosfot, Megilla 5b s.v. “Ubikesh”.
12 Taanit 29a; OC 558:1.
13 Tur, OC 558; OC 558:1; Sha’arei Teshuva 558: 2.
14 Rema, OC 558:1. But see Shu”t Maharshal 92.
15 OC 551:4.
16 Shemirat Shabbat K’hilchata 42:16; Piskei Teshuvot 558:2.
17 Teshuvot V’hanhagot 2:260.
18 Magen Avraham 558:1; Aruch Hashulchan, OC 558:2; Mishna Berura 558:3; Shemirat Shabbat K’hilchata 42:52; Rivevot Ephraim 3:342. See also Be’er Moshe 3:79.
19 Rema, OC 558:1.
20 Mishna Berura 558:3; Kaf Hachaim, OC 558:7.
21 Taanit 29b.
22 Beit Yosef, OC 551; Magen Avraham 551:8.
23 Minchat Elazar 3:66.
24 Siddur Rashi; Machzor Vitri; Bach, OC 551. See also Taz, OC 551:10; Magen Avraham 551:16; Elya Rabba 551:45. (Though even according to this custom it is permitted to do laundry needed in honor of Shabbat.)
25 Taanit 29b.
26 Taanit 30a; Mishna Berura 551:2.