Ézéchiel 16:2 Midrash : Pesikta Rabbati

בֶּן־אָדָ֕ם הוֹדַ֥ע אֶת־יְרוּשָׁלִַ֖ם אֶת־תּוֹעֲבֹתֶֽיהָ׃

"Fils de l’homme, fais connaître à Jérusalem ses abominations.

Pesikta Rabbati

She weeps bitterly in the night (Lamentations 1:2) - Let our teacher the priests teach us - is it permitted for them to immerse for their terumah offering on the Ninth of Av? Rabbi Chanina the deputy High Priest said: It would suffice for the House of our God to forgo one immersion. (Beraisa Taanit 13a) Needless to say, we must recall the destruction of the Temple.