A generous prayer is never presented in vain; the petition may be refused, but the petitioner is always, I believe, rewarded by some gracious visitation.

Robert Louis Stevenson (1850-1894) Scottish essayist, novelist, poet

Story (1882-06), “The Merry Men,” ch. 3, Cornhill Magazine, Vol. 45, No. 6
    (Source)

Collected in The Merry Men and Other Tales and Fables (1887).