بُلُوغُ الْمَرَامِ
Bulugh al-Maram 1117
Marriage
وَعَنْ عُمَرَ - رضى الله عنه - - { فِي اِمْرَأَةِ اَلْمَفْقُودِ- تَرَبَّصُ أَرْبَعَ سِنِينَ, ثُمَّ تَعْتَدُّ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا } . أَخْرَجَهُ مَالِكٌ, وَالشَّافِعِيُّ [1] .
Narrated 'Umar (RA) regarding a wife of a lost husband: She should wait for four years and then observe the 'Iddah for four months and ten days (before she may remarry). [Malik and ash-Shafi'i reported it].
Sunnah.com reference: Book 8, Hadith 181