"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) ."
Sahih al-Bukhari Book 68, Hadith 40
← Previous Hadith 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."

Sahih al-Bukhari Book 68, Hadith 39 Next Hadith → (the Maula of Munba'ith) The Prophet (ﷺ) was asked regarding the case of a lost sheep. He said, "You should take it, because it is for you, or for your brother, or for the wolf." Then he was asked about a lost camel. He got angry and his face became red and he said (to the questioner), "You have nothing to do with it; it has its feet and its water container with it; it can go on drinking water and eating trees till its owner meets it." And then the Prophet (ﷺ) was asked about a Luqata (money found by somebody). He said, "Remember and recognize its tying material and its container, and make public announcement about it for one year. If somebody comes and identifies it (then give it to him), otherwise add it to your property."

Sahih al-Bukhari Book 68, Hadith 41