The Rambam in the Peirush Hamishnayos writes that the problem of לולב הגזול is מצוה הבאה בעבירה. However the Rambam in the Ya"d [Lulav 8-9] says that גזול is only pasul on the first day but not later. This implies that the issue is that it must belong to you ["לכם"] which only applies on the first day and not later.
So which one is it - מצוה הבאה בעבירה or לכם??
