قَالَ مَالِكٌ وَبَلَغَنِي أَنَّ عُمَرَ بْنَ الْخَطَّابِ قَالَ فِي الْمَرْأَةِ يُطَلِّقُهَا زَوْجُهَا وَهُوَ غَائِبٌ عَنْهَا ثُمَّ يُرَاجِعُهَا فَلاَ يَبْلُغُهَا رَجْعَتُهُ وَقَدْ بَلَغَهَا طَلاَقُهُ إِيَّاهَا فَتَزَوَّجَتْ أَنَّهُ إِنْ دَخَلَ بِهَا زَوْجُهَا الآخَرُ أَوْ لَمْ يَدْخُلْ بِهَا فَلاَ سَبِيلَ لِزَوْجِهَا الأَوَّلِ الَّذِي كَانَ طَلَّقَهَا إِلَيْهَا ‏.‏ قَالَ مَالِكٌ وَهَذَا أَحَبُّ مَا سَمِعْتُ إِلَىَّ فِي هَذَا وَفِي الْمَفْقُودِ ‏.‏

Yahya related to me from Malik from Yahya ibn Said from Said ibnal-Musayyab that Umar ibn al-Khattab said, "The woman who loses herhusband and does not know where he is, waits for four years, then shedoes idda for four months, and then she is free to marry." Malik said, "If she marries after her idda is over, regardless ofwhether the new husband has consummated the marriage or not, her firsthusband has no means of access to her." Malik said, "That iswhat is done among us and if her husband reaches her before she hasremarried, he is more entitled to her." Malik said that hehad seen people disapproving of someone who said that one of thepeople (of knowledge) attributed to Umar ibn al-Khattab that he said,"Her first husband chooses when he comes either her bride-price or hiswife." Malik said, "I have heard that Umar ibn al-Khattab,speaking about a woman whose husband divorced her while he was absentfrom her, and then he took her back and the news of his taking herback had not reached her, while the news of his divorcing her had, andso she had married again, said, 'Her first husband who divorced herhas no means of access to her whether or not the new husband hasconsummated the marriage.' " Malik said, "This is what I likethe best of what I heard about the missing man." Translation Not Available

Book Ref: Muwatta Imam Malik Book 29 Hadith 1213
Web Ref:  Muwatta Imam Malik Book 29 Hadith 52