The Holy Prophet (s.a.w.a.) said,
‘Fatima is named Mansoora in the heavens and Fatima on the earth.
She is called Fatima on the earth because her friends are separated (fatim) from the Fire while her enemies are separated from her love.
She is called Mansoora in the heavens because ‘…and on that day the believers shall rejoice, with the help of Allah, He helps whom He pleases…’ (Rum: 5-6) i.e. help of Fatima for her Shias.’
Behaarul Anwaar vol. 43, pages 4-5 narrated from Maanil Akhbaar