Narrated 'Aishah (RA):

Barirah was ordered to wait till three menstrual periods of hers have passed (before she could remarry). [Reported by Ibn Majah. Its narrators are reliable, but it is Ma'lul (having a hidden defect)].

وَعَنْ عَائِشَةَ رَضِيَ اَللَّهُ عَنْهَا قَالَتْ: { أُمِرَتْ بَرِيرَةُ أَنْ تَعْتَدَّ بِثَلَاثِ حِيَضٍ [1]‏ } .‏ رَوَاهُ اِبْنُ مَاجَهْ, وَرُوَاتُهُ ثِقَاتٌ, لَكِنَّهُ مَعْلُولٌ [2]‏ .‏