It is narrated from Imam Baqir (AS) who said:

When Lady Fatimah Zahra (SA) was born, Allah (SWT) revealed to an angel and due to that revelation, the Prophet of Islam (PBUH) called her daughter Fatimah (SA) and then said: I (God) nurtured you with knowledge and have chosen you over other women and elevated your status, and have cleansed any kind of impurity from you. Imam Baqir (AS) continued: Swear to Allah (SWT) that due to covenant with the Prophet (PBUH), God nurtured Lady Fatimah Zahra (SA) and cleansed her from impurities [1]. Jabir Ibn Abdullah Ansari (RA) narrated from the Prophet of Islam (PBUH): Fatimah (SA) is the joy and happiness of my heart, and her children are fruits of my heart, and her husband is the light of my eyes, and the infallible Imams who are from her children are my trustees, and they are like strong rope which are hung by God for people. Whoever grabs them will be saved, and whoever avoids them, will be destroyed [2].

[1] Kashful Qommah,Vol. 2,Page 19.

[2] Beharul Anwaar, Vol. 23, Page 143.

Source: en.shafaqna.com