Q. How come we read the pasuk of Eicha Essa on parshat Devarim and some read the Haftara also with the nigun of Megilat Eicha, is that not Avelut Befarhesia on Shabbat, that is prohibited?

A. Horav Shlomo Miller’s Shlit’a opinion is that our sages often instituted tefilos, such as Av Horachamim, Izkor, Haftoros etc, that contain a sad or mournful theme to be recited or read on Shabbos. This does not represent avelus befarhessia or open grieving, since it is done as an established, generalized tradition of imparting necessary teachings and prayers for all.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a