Musnad Ahmad 1244:2

Ya'qub narrated to us, he said: My father narrated to us, from Salih ibn Kaysan, he said: Muhammad ibn Muslim ibn 'Ubayd Allah ibn Shihab narrated to us, that Humayd ibn 'Abd al-Rahman ibn 'Awf informed him, that his mother, Umm Kulthum bint 'Uqbah, informed him that she heard the Messenger of Allah, may Allah bless him and grant him peace, say: "The liar is not the one who reconciles between people, so he conveys good or says good." And she said: "I did not hear him grant a concession in anything of what people say except in three: in war, in reconciliation between people, and the speech of a man to his wife, and the speech of a woman to her husband." And Umm Kulthum bint 'Uqbah was among the emigrant women who pledged allegiance to the Messenger of Allah, may Allah bless him and grant him peace.