From Sahih Bukhari (Hadith 5291):
Ibn `Umar added:"When the period of four months has expired, the husband should be put in prison so that he should divorce his wife, but the divorce does not occur unless the husband himself declares it. This has been mentioned by `Uthman, `Ali, Abu Ad-Darda, `Aisha and twelve other companions of the Prophet (ﷺ)
Reference: Bukhari 5291