The grandson of the מגן אברהם was a wealthy but miserly man. At every opportunity, he boasted about his יחוס as a descendant of the מגן אברהם. When ר׳ צבי יחזקאל מיכלזאהן asked him for a נדבה for a charitable cause, he refused to give. The רב said to him: “You should know that your grandfather would not have achieved the fame that he did without מחצית השקל, the ביאור on his ספר. Therefore, if you want me and others to recognize you as being a descendant of the מגן אברהם, you have to come up with מחצית השקל.”
05/10/2021