SOURCE: Stutchkoff, Der Oytser fun der Yidisher Shprakh. The evil eye, according to superstition, is a malevolent gaze, motivated by jealousy and causing serious harm. Read about the evil eye in Judaism. Another saying warns:
.אַ ייִדישער עין–הרע איז ערגער פֿון אַ גוייִשן כּישוף
A yidisher eyn-hore iz erger fun a goyishn kishef.
A Jewish evil eye is worse than Gentile witchcraft.
SOURCE: Bernstein, Jüdische Sprichwörter und Redensarten