Reference for Taanit 58:6

מיתיבי אסור לכבס לפני תשעה באב אפילו להניח לאחר תשעה באב וגיהוץ שלנו ככיבוס שלהן וכלי פשתן אין בהם משום גיהוץ תיובתא

For R'Assi said in the name of R'Johanan: When a man has one shirt only he may wash it in the middle days of the Festival.<span class="x" onmousemove="('comment',' Although washing is forbidden on these days. Cf. M.K. 14a, 18b.');">⁷</span> So too it has been stated: R'Benjamin said in the name of R'Eleazar: The restriction applies only to washing clothes for immediate wear but washing clothes for storing is permissible. An objection was raised against this: It is forbidden to wash clothes before the ninth of Ab even for storing them until after the ninth of Ab.

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