【方言】snarl and snap at Lü Dongbin(one of the eight immortals in Chinese mythology )—wrong a kind-hearted person
狗咬吕洞宾，不识好人心
like the dog that bit Lü Dongbin,you bite the hand that feeds you—mistake a good man for bad one
狗咬吕洞宾，不识好人心ɡǒu yǎo lǚ dònɡ bīnɡ ,bù shí hǎo rén xīn
狗咬了常做善事的吕洞宾。比喻不识好和坏。mistake a good man for a bad one, wrong a kind hearted person