Do not sound a trumpet before thee, as the hypocrites do - The word “hypocrite” is taken from “stage-players,” who act the part of others, or speak not their own sentiments, but the sentiments of others. It means here, and in the New Testament generally, those who “dissemble” or hide their real sentiments, and assume or express other feelings than their own - those who, for purposes of ostentation, gain, or applause, put on the appearance of religion. It is probable that such persons, when they were about to bestow alms, caused a trumpet to be sounded, professedly to call the poor together to receive it, but really to call the people to see the proofs of their liberality and piety; or perhaps it may mean that they should not make a great noise about it, like sounding a trumpet.
In the synagogues - The word “synagogue” commonly means the place of assembling for religious worship known by that name. See the notes at Matthew 4:23. It might mean, however, any “collection of people” assembled for any purpose, and it is not improbable that it has that meaning here. It does not appear that they made a noise in bestowing charity in the synagogues, or that charity was commonly bestowed there; but it was probably done on occasion of any great assemblage, in any place of concourse, and at the corners of the streets, where it could be seen by many.
They have their reward - That is, they obtain the applause they seek the reputation of being charitable; and as this applause was all they wished, there is, of course, no further reward to be looked for or obtained.