Midrasch zu Mischlej 17:10

Further said R. Jochanan in the name of R. Jose: "One chastisement in the heart of man (self reproach) is better than many lashes, as it is said (Hos. 2, 9.) And she will pursue her lovers, then will she say, 'I will go and return to my first husband; for if was better with me then than now.'" Resh Lakish said: "It is better than one hundred stripes, as it is said (Pr. 17, 10.) A reproof penetrateth more deeply into a wise man than a hundred lashes into a fool."