Chapter 122:17 Between the 17th of Tammuz and Tisha B'av
17. It is customary to honor the Rabbi with maftir on Shabbos Chazon (the
Shabbos before Tish'ah B'av), since he knows how to [recite the Haftorah]
mournfully ("le'konein") [as is appropriate] (1). Therefore, he should not
be given the third aliyah [on this Shabbos] (2).
(1) As opposed to the regular tune for the Haftorah.