Weak
graded by Al-Albani
Mishkat al-Masabih 6154
وَعَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ لِعَلِيٍّ وَفَاطِمَةَ وَالْحَسَنِ وَالْحُسَيْنِ: «أَنَا حَرْبٌ لِمَنْ حَارَبَهُمْ وَسِلْمٌ لِمَنْ سَالَمَهُمْ» . رَوَاهُ التِّرْمِذِيّ
He told that God's messenger said of `Ali, Fatima, al-Hasan and al-Husain, "I am war to him who makes war on them and peace to him who makes peace with them." Tirmidhi transmitted it.
Cited in Mishkat al-Masabih (No. 6154).