Matthew 6:2-4

2So whenever you do tzadakah, do not sound a trumpet before you as the hypocrites do in the synagogues and on the streets, so that they may be glorified by men. Amen, I tell you, they have their reward in full!

3But when you do tzadakah, do not let your left hand know what your right hand is doing,

4so that your tzadakah may be in secret; and your Father, who sees in secret, shall reward you.