It is narrated from Sayyiduna Siyabah bin Asim al-Sulami (may Allah be pleased with him) that on the day of the Battle of Hunayn the Messenger of Allah (peace and blessings be upon him) said: "I am the son of the Awatik (the lineage of pure mothers)."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6694