Hadith 118

Bulugh al-Maram

Book 8: Marriage
وَلِأَحْمَدَ : مِنْ حَدِيثِ سَهْلِ بْنِ أَبِي حَثْمَةَ : { وَكَانَ ذَلِكَ أَوَّلَ خُلْعٍ فِي اَلْإِسْلَامِ } 1‏ .‏
Ahmad reported from Sahl bin Abu Hathma's Hadith that it was the first ever husband and wife separation for compensation in Islam.