It is narrated from Alqamah (may Allah have mercy on him) that a woman came to Sayyiduna Umar (may Allah be pleased with him) and said: My husband divorced me, then left me until I had closed my door, set out my water (for bathing) and taken off my clothes; then he said: I have taken you back, I have taken you back.
Sayyiduna Umar (may Allah be pleased with him) said to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), who was sitting at his side: What do you say about this woman? Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: My view is that her husband is more entitled to her until she takes the bath from her third menstruation and prayer becomes lawful for her. Sayyiduna Umar (may Allah be pleased with him) said: That is my view about it as well.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب العدد / 15394