狗嘴里长不出象牙

狗嘴里长不出象牙 [gǒu zuǐ li zhǎng bù chū xiàng yá]

1. ■ No ivory will come of a dog's mouth.; A cracked bell can never sound well.; A filthy mouth can't utter decent language.; No ivory issues from the mouth of a dog; One cannot expect to find elephant tusks in the mouth of a dog -- A mean fellow never speaks nice things.; One doesn't expect ivory from a dog's mouth.; You can't make a silk purse out of a sow's ear.; You don't find ivory in a dog's mouth.