Abu Bakr and Umar proposed marriage to Fatimah, but the Messenger of Allah ﷺ said, "She is still young." Then Ali proposed to her, and he married her to him.
أخبرنا الحسين بن حريث قال حدثنا الفضل بن موسى عن الحسين بن واقد
خطب أبو بكر وعمر رضي الله عنهما فاطمة فقال رسول الله ﷺ إنها صغيرة فخطبها علي فزوجها منه
Its isnad is sahih. Ibn Hibban transmitted it in his Sahih, hadith no. 2224, from the hadith of Husayn bin Hurayth, by this route, and it is in Kubra, hadith no. 5329. Hakim graded it sahih on the criteria of the two sheikhs, 2/167, 168, and Dhahabi agreed with him, but it is only on the criteria of Muslim alone.