It is narrated from Sayyiduna Ali (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "I was born of the pure bond (of lawful marriage), and I was not born of fornication. This sound lineage of mine continued (pure in the same way) from Adam (peace be upon him) until my birth through my parents, and no fornication of the time of Ignorance touched me in the least."
(Takhrij: Imam al-Tabarani narrated it in al-Mu'jam al-Awsat [4728] and Imam al-Bayhaqi in Dala'il al-Nubuwwah, and on the basis of several supporting reports this hadith is of the hasan (good) grade.)
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب السيرة والمغازي / 4210
Hadith Gradingمحدثین:إسناده ضعيف، مرسل
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :مرسل، إسناده ضعيف. » «أخرجه المعجم الأوسط للطبراني برقم: 4728»