It is narrated from Umm Bakrah Al-Aslamiyyah that she took khul‘ from her husband Abdullah bin Asid, then both of them brought this matter to ‘Uthman (may Allah be pleased with him). He said: "If you have mentioned something else, then it is what has been mentioned; if not, then it is a divorce."
Hadith Referenceمسند الإمام الشافعي / كتاب عشرة النساء والإيلاء والخلع / 1235
Hadith Takhrijاسناده ضعیف فان جمهان مقبول حديث يتابع ولم يتابع عليه اخرجه البيهقى 7 / 316 - وفي المعرفة السنن والآثار له (4398)۔