Why don't we say Avinu Malcanu on Tisha B' Av?
The Artscroll Siddur says "on fast days that tachanun is omitted...", is there any other reason?
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Sign up to join this communityWhy don't we say Avinu Malcanu on Tisha B' Av?
The Artscroll Siddur says "on fast days that tachanun is omitted...", is there any other reason?
My rav explained that Tachanun (which, is part of your question, per se, not necessarily the direct reason why Avinu Malkeinu) is omitted on occasions of either "extreme" - extreme joy or extreme sadness.
Yom Tov is "extreme joy" so Tachanun is omitted.
In a house of mourning during the week of shiva, Tachanun is also omitted. This is a location & time of extreme sadness.
If Tachanun is omitted in a house of mourning where one person is mourning, kal vachomer it should be omitted when all of B'nei Yisra'el is mourning!
The main reason that I recall is because of the pasuk in Eichah (1:15) that refers to the day as "moed"
קָרָא עָלַי מוֹעֵד לִשְׁבֹּר בַּחוּרָי
I don't remember why that forces a connection.
Edited to change my answer. Here is a link that explains why we don't say Avinu Malkeinu on Tisha B'Av.