The messenger of Allah (PBUH&HF) said to Fatimah (AS) that: "I gave you in marriage to the best in my Ummah, the most knowledgeable in them, the best in patience in them, and the first Muslim among them."
Sunni reference: Kanz al-Ummal, by al-Muttaqi al-Hindi, v6, p398
The Messenger said to his daughter Fatimah al-Zahra (AS): "Would it not please you that I have married you to the first Muslim in my nation, their most knowledgeable, and their greatest in Wisdom."
Sunni reference: Musnad Ahmad Ibn Hanbal, v3, p136; v5, p26