Here "it" refers to the false accusations of the writer's enemies. Alternate translation: "You have seen how they falsely accused me" (See: [[rc://en/ta/man/translate/figs-explicit]])
"do not ignore what they did" This can be stated in positive form. Alternate translation: "judge them because of what they did" (See: [[rc://en/ta/man/translate/figs-litotes]])