But you, when you give to the needy, do not let your left hand know what your right hand is doing.
In this saying Jesus teaches the perfect form of mercy: when it is done with complete sincerity, without show and without any thought of self-praise. The phrase, “Let your left hand not know what your right hand is doing,” symbolizes such secrecy and humility that even the person himself should not glorify his deed or remember it as a merit. True mercy is born from love and a pure heart, without ulterior intention, so that no one, even the one who gives mercy, can attribute his goodness to his own merits. This saying teaches that God sees what is hidden, and He is the One who evaluates every work according to the purity of the heart.