Kiddush Levanah
42. We say Kiddush Levanah on Motzei Tishah B’Av (באר היטב תקנ"ט כ"ה בשם האר"י ). This is because Moshiach ben Dovid is born on Motzei Tishah B’Av, so we “inform the moon” and Klal Yisroel that they are going to be renewed. May we hear this news this year.
43. It is preferable to put on shoes and taste something before saying Kiddush Levanah since one should only greet the Shechinah when he is happy, smells good, and is wearing nice clothing.
The Tenth of Av
44. The Beis Hamikdash caught fire on the 9th of Av, toward evening, and it burned through shkiyah of the 10th. Therefore, certain aspects of aveilus apply on the 10th (שו"ע סי' תקנ"ח ), as will be explained. Although the Beis Hamikdash burned mostly on the 10th, Chazal instituted aveilus primarily on the 9th since that was when the tragedy began (מ"ב סק"א בשם הגמ').
45. The Mechaber writes that it is proper to abstain from meat and wine on the night and day of the 10th (שו"ע שם ). This implies that the issur to eat meat or drink wine applies all day. However, it is clear that the Mechaber holds that the other aspects of aveilus are muttar. This is the Sephardi minhag (שו"ת אור לציון ח"ג פכ"ט תשו' כ"ו).
46. The Rama mentions that some people only practice aveilus until chatzos of the 10th. The minhag is to not wash, cut hair, or do laundry until chatzos (מהרש"ל, מ"ב סק"ג ) Other practices of the Nine Days, e.g., not mending clothes, not wearing fresh clothes, and not listening to music, are also followed until chatzos of the 10th (מג"א, מ"ב סק"ב ).
Extenuating Situation
47. In a hot locale, one who is very uncomfortable may wash on motzei Tish’oh B’ov and the 10th of Av in a manner which is muttar during the Nine Days, i.e., with warm water, limb by limb etc. (see Gilyon 50), since the 10th is slightly more lenient than the Nine Days, not stricter (מאמר מרדכי הובא בביאה"ל ד"ה עד, תשובות והנהגות ח"ב סי' ר"ס ).
48. One who is leaving on the morning of the 10th for an extended period may do laundry on motzei Tish’oh B’ov if necessary (קובץ מבית לוי בין המצרים עמ' ל''ח).
