The Hebrew text on the Golem is 'emet' or truth. Removing the first consonant (the aleph) the word reads 'dead' and is the way to kill the Golem.
Early in the film, after the rabbi declares three days of mourning, he tears a part of his clothing. The tearing of one's clothes is a tradition stretching back thousands of years among Jewish people, and was a way to outwardly express grief, mourning, or loss. There are instances of this practice mentioned in stories in the Jewish Tanakh (and for Christians, the Old and New Testaments).
During the scene when Benjamin and Hanna are arguing, at one point he says that she hasn't put a rock on their child's gravestone. Placing a rock on someone's gravestone is an ancient Jewish custom to indicates that one has visited and paid homage to the deceased. (It has since been adopted as a custom among some Christians as well). When Benjamin says Hanna has not placed a rock, he is indicating she has never visited the gravesite and, in his mind, does not mourn her son as much as she should.