花言巧語／ 花言巧语 ( huāyánqiǎoyǔ): means flowery but insincere language. Pretty but opportunistic speech. Wiktionary

自相矛盾 ( zìxiāngmáodùn): means ‘to contradict yourself’. "Translated as ‘to contradict yourself’ the first two characters, 自相 ( zìxiāng), mean ‘self’ whilst 矛盾 ( máodùn) literally mean ‘spear’ and ‘shield’ respectively. This Chinese expression comes from an old Chinese story where a man selling swords and shields at a market claimed first that his spears were so sharp that they could pierce through any armor. He then claimed that his shields were so strong they could resist any blow, thus contradicting himself. From that story ‘spear and shield’ has become synonymous for contradiction" . Wiktionary