The Messenger of Allah ﷺ said to Ali, Fatimah, Hasan, and Husayn, "I am at war with whoever wars against you, and at peace with whoever is at peace with you."
حدثنا سليمان بن عبد الجبار البغدادي حدثنا علي بن قادم حدثنا أسباط بن نصر الهمداني عن السدي عن صبيح مولى أم سلمة
أن رسول الله ﷺ قال لعلي وفاطمة والحسن والحسين أنا حرب لمن حاربتم وسلم لمن سالمتم
[Its isnad is daif] Ibn Majah narrated it in the Muqaddimah, chapter on the merit of Hasan and Husayn, the two sons of Ali bin Abu Talib , hadith no. 145, from the hadith of Asbat bin Nasr with this same wording, and Ibn Hibban graded it sahih (al-Ihsan): 6938. Subayh was not deemed reliable by anyone other than Ibn Hibban.