Quote Originally Posted by Demonic_Duck View Post
Sounds like straightforward moralising to me
As a first approach - yeah, but as usual with classical quotations there is much more behind if one knows the source. It was not by Chekhov directly but by his fictitious hero.

BTW Most well-known collection of moralizing in Russian classic literature often can be found on humor sites. Warning: no way of adequate translation.

Quote Originally Posted by Demonic_Duck View Post
Also why is it «лжа»? I can't see that in the declensions of «ложь»...
That fictitious hero found that it sounds better. More aphoristic. Тля-ржа-лжа is a kind of rhyme.