Sayyidah Aishah Siddiqah (may Allah be pleased with her) says: I used to see the Prophet (peace and blessings be upon him) kissing Sayyidah Fatimah (may Allah be pleased with her). I said: O Messenger of Allah! I have seen you doing something which I do not think you used to do before. The Prophet (peace and blessings be upon him) said to me: O Humayra! On the night I was taken up to the heaven on the Mi'raj, I was admitted into Paradise. I stopped at a tree there; I did not see in Paradise any tree more beautiful than it or whiter than it, nor one whose fruit was purer. I took one of its fruits and ate it, and it became a drop of seed in my loins. When I came down to the earth, I had marital relations with Khadijah, and she conceived through it. So whenever I long to smell the fragrance of Paradise, I smell the fragrance of Fatimah. O Humayra! Fatimah is not like ordinary women, and she has not been afflicted with ailments the way people are afflicted.
Imam al-Tabarani recorded this narration. Its chain contains a narrator, Abu Qatadah al-Harrani, whom Imam Ahmad declared thiqah (trustworthy). He said: He used to strive for truthfulness; and Imam Ahmad rejected the view of whoever attributed lying to him. Imam al-Bukhari (may Allah have mercy on him) and others declared this narrator da'if (weak), and some said: He is matruk (abandoned). The chain of this narration also contains narrators whom I do not know. This hadith is mentioned in the book Mizan al-I'tidal under this narrator.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 15197