The word "Tazkiah" has been mentioned several times and in different forms in the Holy Quran. It means the attestation of someone's honorable record, or to purify one's self. For instance, the following verses spoke of "Tazkiah":
(Truly he succeeds that purifies it,) (91: 9)
(Hast thou slain an innocent person,) (18: 74)
((To announce) to thee the gift of a holy son.) (19: 7)
(That is (the course making for) most virtue and purity amongst you.) (2: 232)
The meaning of the first verse is to purify one's self from evil characteristics which develop from corrupt nutrition, excessive speech, anger, envy, greed, self and material worship, conceit and vanity. This type of purification is performed by abandoning such traits and adhering to the noble characteristics which contradict the above mentioned ones.
The second verse means: Have you killed someone who, I attest to his honorable record, for he has not committed a crime or an action, which necessitates punishing.
The third verse speaks of granting a prophet a virtuous son made pure from all sins, and whose nations conform to goodness.
Lady Fatima Zahra (A) is Zakiyah in all the above-mentioned meanings. This is understood from the verse of purification, which we have already discussed, and concluded that She was pure of all abominations or "Rijs."
As for the fourth verse, you can refer to the study in regard to her name "Al-Mubarakah", for here we have explained the purification meant in this verse.
* Fatima ['a] The Gracious.By Abu Muhammad Ordoni.Published by: Ansariyan Publications Qum, The Islamic Republic of Iran. Reproduced with permission by the Ahlul Bayt Digital Islamic Library Project team.