Haftarah
Devarim is always read on the final Shabbat of Admonition, the Shabbat immediately prior to Tisha B'Av. That Shabbat is called Shabbat Chazon, corresponding to the first word of the haftarah, which is Isaiah 1:1–27. Many communities chant the majority of this haftarah in the mournful melody of the Book of Lamentations due to the damning nature of the vision as well as its proximity to the saddest day of the Hebrew calendar, the holiday on which Lamentations is chanted.
Read more about this topic: Devarim (parsha)