The Chazon Ish once answered a student’s question with the following:

“You should know that there are many ways of finding merit. A boy without remarkable abilities may nevertheless try hard and achieve success -- all in the merit of a mother or grandmother or even a great-grandmother who, as she lit the Shabbos candles, let fall a warm tear or two as she prayed from the depths of her heart that her descendants might be Torah scholars and rise to heights in Torah. The merit of that mother or grandmother’s tears assists that boy to become great in Torah.”