Based narrations, Imam Ali (AS) washed ceremonially the body of Hazrat Fatima Zahra(SA).
Imam Jafar Sadiq (AS) was asked: Who washed ceremonially the body of Hazrat Zahra
He responded in an answer "Imam Ali (AS)!; because Hazrat Fatima Zahra(SA) was SIDDIQA (truth-teller) and nobody was allowed to wash her except Imam Ali (as) who was a truth teller himself as well.
Although it has been mentioned in some narrations that Asma bint Umais also helped Imam Ali (as) in washing Hazrat Fatima Zahra (SA) body and he is quoted as saying: Hazrat Fatima Zahra(SA) has made a will that nobody shouldn’t wash me except for you and Imam Ali (AS), she was asking for such a will that Imam Ali (AS) and I washed her ceremonially.
(SA)?
source : erfan.ir