Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrated that the Messenger of Allah (peace and blessings be upon him) came to Ali and Fatimah (may Allah be pleased with them both) while the two of them were laughing. When they saw the Prophet (peace and blessings be upon him), they fell silent. So the Prophet (peace and blessings be upon him) said to them: "What is the matter with you two? You were laughing, and when you saw me you fell silent?" Fatimah (may Allah be pleased with her) hastened to say: May my father be sacrificed for you, O Messenger of Allah! He (that is, Ali) said: I am more beloved to the Messenger of Allah (peace and blessings be upon him) than you. So I said: Rather, I am more beloved to the Messenger of Allah (peace and blessings be upon him) than you. So the Messenger of Allah (peace and blessings be upon him) smiled and said: "O my little daughter! You have the tenderness of a child, and Ali is dearer to me than you."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11017