"blow the trumpet" - like the tune of an ice cream truck, the trumpet announced the imminent generosity of the giver to the clients as well as to the admiring crowd. Like government entitlement, the largess went only to those able to come. As with entitlements, many came who were not the most in need - or not in need at all. The Pharisee did not go himself or send a servant to the seedy part of town, or to the highways and the byways (Luke 14:23), to identify those desperate and unable to come to the trumpet and "strengthen the hand of the poor." Ezekiel 16:49 The Pharisee did not notice the poor (Galatians 2:10) who came to his trumpet, his attention was for the admiring crowd.
From Rockefeller throwing dimes to Chen handing out $100 bills, we have similar handouts today (although Chen says he just wants other people to notice the poor).