mǎ lù yì xíng
to distinguish horse and deer easily
to know right from wrong
马
mǎ
abbr. for Malaysia 馬來西亞|马来西亚[Ma3 lai2 xi1 ya4]
鹿
lù
deer
易
yì
abbr. for 易經|易经[Yi4 jing1], the Book of Changes
形
xíng
to appear