Matthew 6:3
1 “Be careful not to display your righteousness merely to be seen by people. Otherwise you have no reward with your Father in heaven. 2 Thus whenever you do charitable giving, do not blow a trumpet before you, as the hypocrites do in synagogues and on streets so that people will praise them. I tell you the truth, they have their reward! 3 But when you do your giving, do not let your left hand know what your right hand is doing, 4 so that your gift may be in secret. And your Father, who sees in secret, will reward you. 5 “Whenever you pray, do not be like the hypocrites because they love to pray while standing in synagogues and on street corners so that people can see them. Truly I say to you, they have their reward! 6 But whenever you pray, go into your inner room, close the door, and pray to your Father in secret. And your Father, who sees in secret, will reward you.
Bava Batra 9b
Babylonian Talmud§ The Gemara resumes its discussion of the virtues of giving charity. Rabbi Elazar said: One who performs acts of charity in secret is greater than Moses, our teacher. Whereas with regard to Moses, our teacher, it is written: “For I was afraid of the anger and the wrath” (Deuteronomy 9:19), with regard to one who performs acts of charity it is written: “A gift in secret pacifies anger, and a present in the bosom fierce wrath” (Proverbs 21:14). The Gemara comments: And this statement disagrees with a statement of Rabbi Yitzḥak, as Rabbi Yitzḥak says: A secret gift pacifies anger, but it does not pacify wrath, as it is stated: “And a present in the bosom fierce wrath,” meaning that although a present is in the bosom, i.e., even if one gives charity in secret, nevertheless fierce wrath can still harm him. There are those who say that Rabbi Yitzḥak says as follows: Any judge who accepts a bribe brings fierce wrath upon the world, as it is stated: “And a present in the bosom fierce wrath.”
Notes and References
"... The rabbinic tradition expresses the same spirit as Jesus in Matthew: “He who gives tzedaqah in secret is greater than Moses” (b. Bava Batra 9b). The story is told that Rabbi Yannai “once saw a man give money to a poor man publicly. He said: ‘It had been better that you gave him nothing than that you should have given to him and put him to shame’” (b. Hagigah 5a). There was also a tradition in the temple of “the Vestry of the Secret Ones,” in which people could place alms so that those who were in need “might be helped in secret” (m. Sheqalim 5.6). Matthew’s use of “hypocrites” is typical ancient name-calling; “brood of vipers” and “whited sepulchers” are other instances. We do well to remember that each of us is to some extent a hypocrite, and that hypocrisy does not distinguish one faith community from another ..."
Allen, Ronald J. Preaching the Gospels without Blaming the Jews: A Lectionary Commentary (p. 27) Westminster John Knox Press, 2004