Musar for Bava Batra 329:4

[And see, now my brother, that according to the epitomization of Chazal (Bava Bathra 165a), that all [men stumble] in lashon hara, there is no issur in the world that is as "abandoned" as that of lashon hara. For in theft, only the majority stumble; but in lashon hara, all! And even though they have said that this applies only to the "dust" of lashon hara and not to lashon hara itself, Rambam of blessed memory has already written: "Would that we guarded ourselves from the issur itself!" If so, there is no other mitzvah that has been abandoned to this extent. And one who strengthens himself in it, in truth, accords honor to the mitzvah, and it will ascribe merit to him above for doing so.]

Along these lines they said (Bava Batra 165a): "the majority of people are guilty of [forms of] theft, a minority in immorality, but all are guilty of the dust of slander" (i.e. traces of slander). For due to its extremely fine details, all human beings stumble in what they fail to recognize of it.

FORBIDDEN RELATIONS: Let us now discuss the topic of forbidden relations. They are also among the sins people crave and are ranked second to theft as our sages, of blessed memory, said "the majority of people are guilty of theft and a minority of illicit relations" (Bava Basra 165a).