I once heard (I do not recall from who or where) that The Vilna Gaon once remarked that the way to determine if one's actions were in fact a good deed, one must look at the after effects. The Gr"a is interpreting the Mishna in Pirkei Avot: מצוה גוררת מצוה – one mitzvah leads to another mitzvah.
Does anyone know where such a Gr"a can be found.
Or if this is mis-attributed to the Gra, and really someone else said this.
Or maybe someone has heard a similar idea from somewhere else.