(21) بَابُ قَوْلِ اللَّهِ تَعَالَى: {لِلَّذِينَ يُؤْلُونَ مِنْ نِسَائِهِمْ تَرَبُّصُ أَرْبَعَةِ أَشْهُرٍ} إِلَى قَوْلِهِ: {سَمِيعٌ عَلِيمٌ} {فَإِنْ فَاءُوا} رَجَعُوا
Narrated Nafi`:
Ibn `Umar used to say about the Ila (which Allah defined (in the Holy Book), "If the period of Ila expires, then the husband has either to retain his wife in a handsome manner or to divorce her as Allah has ordered."
Reference: Sahih al-Bukhari 5290
In-book reference: Book 68, Hadith 39
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 7, Book 63, Hadith 213