Humayd bin Abd al-Rahman (may Allah have mercy on him) narrates from his mother, Umm Kulthum bint Uqbah (may Allah be pleased with her), that she said: I heard the Messenger of Allah (peace and blessings be upon him); he (peace and blessings be upon him) permitted lying only on three occasions, and he used to say: "I do not count him a liar: 1. one who reconciles between people, intending nothing but reconciliation; 2. on the occasion of war; 3. a wife saying something to her husband, or a husband to his wife."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20833