Hilchos Lashon Hara, Opening – positive commands (8)

Whoever speaks lashon hara about an old person and puts him down to his face breaks the positive commandment (Vayikra 19:32), "You shall honor the face of the old person." This means it is a mitzvah to speak respectfully in front of him - and if one puts him down, he is surely not honoring him.

Speaking lashon hara about a Torah scholar, even a young one, also breaks this mitzvah, because the "zaken" (elder) in the verse also means a Torah scholar. If he is both old and a Torah scholar, the mitzvah is broken twice.