What advice does Grampa give Hiram about testifying in the trial?

Hiram takes the summons to Grampa who says that he would prefer if Hiram stays out of things, or at least not tell everything he knows about R.C. Hiram feels afraid as well, but he insists that he tell what he knows. This begins an argument between Grampa and Hiram. At first, Grampa seems to be concerned for Hiram's well being. As the argument wears on, Grampa finds other excuses for Hiram not to involve himself in the trial. Among those are the fact that Hiram did not actually witness any wrongdoing and that all he heard was just R.C. talking, then Grampa flips it to how Emmett got what he deserved, and finally to his reason of not wanting Hiram to be an embarrassment to the family. Grampa explains that when Harlan was younger people would look down on Grampa behind his back because Harlan did not go along with the ways of the South and that it caused Grampa a great deal of embarrassment. This news greatly upsets Hiram, but he is still determined to do what is necessary.