Sahih Muslim Book 45, Hadith 131
This hadith has been narrated on the authority of Ibn Shihab with the same chain of transmitters but with a slight variation of wording.
A liar is not one who tries to bring reconciliation amongst people and speaks good (in order to avert dispute), or he conveys good. Ibn Shihab said he did not hear that exemption was granted in anything what the people speak as lie but in three cases: in battle, for bringing reconciliation amongst persons and the narration of the words of the husband to his wife, and the narration of the words of a wife to her husband (in a twisted form in order to bring reconciliation between them).
This hadith has been transmitted on the authority of Zuhri with a slight variation of wording.