Hitler had a number of negative things to say about the Jews, but the most notable was probably "untermenschen," which translates roughly to "the subhumans." He commonly referred to them as filth or contaminants threatening his "master race," the Aryans.
Hitler also used symbolism to target the Jews. Early on, shops owned by Jews were required to display a yellow Star of David or the word "Juden" on windows and doors; later, the Jews were required to sew a similar star to all their clothing. According to the History Learning Site, these anti-Jewish laws made it easier for anti-Semites to target Jewish people on Kristallnacht, when Jewish shops and homes were vandalized or burned, and later to locate Jews for imprisonment in concentration camps.