Therefore, when you do your alms, do not sound a trumpet before you, as the hypocrites do in the synagogues and the streets, that they may have the glory of men. Truly I say to you; they have their reward (Matthew 6:2).
In Temple times, there were receptacles called “trumpets” in the synagogues and throughout Jerusalem, where givers could place (donate) alms for the poor. These well-recognized containers were made of brass and had a large opening at the top and a narrow pipe that led to a collection basin at the bottom, and as such, they resembled trumpets—hence the name. Quite often, if one wanted to get the attention of the crowds, they could pour a large number of coins into the trumpet, which created quite a ruckus. This sound effect would bring much attention to the “giver” and allow this boastful person to relish in a religious attraction (that, in reality, was nothing but hypocrisy.) Yeshua teaches there is no heavenly reward in this kind of boastful action. The only reward for a boastful giver is the selfish satisfaction of self-aggrandizement.
The English saying, “One should not toot their own horn,” most likely comes from this ancient Hebrew idiom.