She heard the Messenger of Allah ﷺ say, "The one who reconciles between people, conveying something good or saying something good, is not a liar."Muslim added, Ibn Shihab said, "I did not hear any of what people call lying being permitted except in three cases, war, reconciling between people, and what a man says to his wife and what a woman says to her husband."
أنها سمعت رسول الله ﷺ يقول: ليس الكذاب الذي يصلح بين الناس، فينمي خيرا، أو يقول خيرا. زاد مسلم: قال ابن شهاب: ولم أسمع يرخص في شيء مما يقول الناس كذب إلا في ثلاث: الحرب، والإصلاح بين الناس، وحديث الرجل امرأته وحديث المرأة زوجها.
Bukhari narrated it in the Book of Reconciliation (2692), and Muslim in the Book of Righteousness and Maintaining Ties (2605), both through routes stating that Humayd bin Abdul-Rahman informed him, that his mother Umm Kulthum bint Uqba informed him, and he related it. The addition is from Muslim's version.In some narrations it occurs, "She said (meaning Umm Kulthum), and I did not hear him permit... " to the end. The correct view is that this is an insertion from the words of Zuhri, as was affirmed by Musa bin Harun, Khatib, Ibn Hajar, and others. See Al-Fasl lil-Wasl al-Mudraj (1/258–275), and Fath al-Bari, commentary on hadith (2692).