What is the ruling regarding a woman who has initiated Khulʿ returning to her husband?

If a woman expends money to gain her independence, and separation occurs through the pronouncement of khulʿ (divorce at the wife's instance), she may not return to her husband except with a new contract. The preponderant opinion is that khulʿ is an irreversible divorce (ṭalāq bāʾin). They cite as evidence His — Exalted be He — saying: "for what she gave in compensation" [Quran 2:229], and that the purpose of khulʿ is to remove harm from the woman.