Or HaChaim on Numbers 12:14/אור החיים על במדבר י״ב:י״ד

1 ואביה ירוק ירק, "if HER father had spit in her face, etc." The Torah emphasises Miriam's experience as that of a daughter of G'd, i.e. a צדקת, rather than that of any father spitting at any daughter.

2The repetition of ירוק ירק indicates that had Moses prayed sooner on her behalf, her Father (G'd) would not have spat at her at all, i.e. she would not have been punished at all. The words ואביה ירוק describe a situation which already existed, meaning that Moses had allowed her father to punish her before intervening. All Moses could do now was to prevent further punishment or extension of the punishment, i.e. "spitting" a second time.

3תסגר שבעת ימים, she must remain quarantined for seven days. It appears that as a result of Moses' prayer the Tzoraat disappeared at once. G'd decreed that she had to remain as an outcast. Had this not been so the Torah would have had to add "until she has been cured from her Tzoraat." It is obvious, therefore, that she had already been cured. This is also the reason the Torah did not mention the fact that she had been healed at the time it reports that she rejoined the camp of the Israelites. Acording to Zevachim 102 the reason that Aaron did not inspect Miriam's affliction either at the beginning or at the end [as is the duty of the priest who has to certify such healing having taken place Ed.] is because as her brother he was disqualified from doing so. According to our interpretation we need not even raise the question of who declared Miriam afflicted or healed seeing she had been healed before Aaron or any other priest had a chance to examine her. As a result, the only restriction Miriam would have had to undergo was quarantine, pending an inspection. Alternatively, G'd Himself performed the function of the priest and declared her as liable to quarantine. Her purification also occurred at G'd's inspection and that is the meaning of the words ואחר תאסף, "afterwards she may be brought in."