言不由衷　

◎ 言不由衷 yánbùyóuzhōng

[speak with one‘s tongue in one‘s cheek;say what one does not mean] 所說的話不是發(fā)自內(nèi)心。形容口是心非

言不由衷,質(zhì)無益也。——《左傳·隱公三年》