…if they’re tzaddikim and the secret is hidden helpfulness
陰徳陽報
in.toku.you.hou
Literally: yin/negative/shadow/secret – virtue – yang/positive/sunlight – reward
Alternately: Performing acts of benevolence and charity in secret will nonetheless benefit the doer. It’s tempting to publicize one’s good deeds in hopes of winning acclaim in society, but karma is sure to even (or especially) reward good deeds that are hidden from public knowledge.
Notes: Note also the post on 因果応報; good-aligned variant 善因善果 (zen.in.zen.ka) is considered a synonym of today’s compound.
This yojijukugo comes to us from our friend the Huainanzi (淮南子, Enanji or, rarely, Wainanshi), in the chapter on “In the World of Man” (人間訓, Ningen-kun).
I like this one because it accords well with the Maimonides’ hierarchy of charity (bottom of page), in which the second-highest level is “giving when neither party knows the other’s identity.” (The absolute best is considered to be charity that allows the recipient to become self-reliant thereafter; i.e. teaching someone to fish is better than any manner or volume of fish-donation.)

Rabbi Moses ben Maimon