Janabe Masooma e Qum (as)

When Imām al-Ridā, peace be on him, was in Khurasān, he wrote to the pure lady Fātima, better known as lady Ma‘sūma; he asked her to come to him, for she was a favorite with him and dear to him. When the letter came to her, she prepared herself and traveled to him.[1] When she arrived at Sāwa, she fell ill. So she asked about the distance between Sāwa and Qum, and it was said to her: “Ten  leagues.” So she ordered the people to carry her to Qum, and they carried her to it. She stopped at the house of Mūsā b. Khazzrajj while she was holding the reins of her she-camel. He brought her to his house, and she stayed in it for seventeen days. Then she died, and Mūsā prepared her for burial. He buried her in his own land and built over her holy grave a shelter of reed mats. (Such was her grave) until a dome was built over it by lady Zaynab, daughter of Mohammed b. ‘Ali al-Jawād.[2] Her Holy Shrine have become one of the dearest places of worship and one of the Holy Shrines in Islam; likewise, that Sacred City has become one of the universities of knowledge and among the cultural centers in Islam.
Al-Hasan b. Mohammed al-Qummi says: “I was (sitting) with Imām al-Sādiq, peace be on him, and he said: ‘Surely Allah has a sacred city, and it is Mecca; His Messenger, may Allah bless him and his family, has a sacred city, and it is Medina; the Commander of the faithful has a sacred city, and it is Kūfa; we have a sacred city, and it is Qum wherein a woman called Fātima from among my children will be buried; whoever visits her, the Garden is obligatory for him.” Imām al-Sādiq had announced that before she was born. ( Tuhfat al-'Ālam, p. 36. Al-Bihār.)

Reference :The life of Imām'Ali Bin Mūsā al-Ridā