道高一尺,魔高一丈 [ㄉㄠˋ ㄍㄠ ㄧ ㄔˇ , ㄇㄛˊ ㄍㄠ ㄧ ㄓㄤˋ; dao4 gao1 yi1 chi3 , mo2 gao1 yi1 zhang4] virtue is one foot tall, the devil ten foot (idiom); It takes constant vigilance to stave off evil. ◄ ►